diff --git a/appinfo/info.xml b/appinfo/info.xml
index 01b372f99b..03af0e9d64 100644
--- a/appinfo/info.xml
+++ b/appinfo/info.xml
@@ -99,6 +99,8 @@ Learn more about the Nextcloud Ethical AI Rating [in our blog](https://nextcloud
 	</commands>
 	<settings>
 		<admin>OCA\Mail\Settings\AdminSettings</admin>
+		<admin>OCA\Mail\Settings\ProviderAccountOverviewSettings</admin>
+		<admin-section>OCA\Mail\Settings\Section\MailProviderAccountsSection</admin-section>
 	</settings>
 	<navigations>
 		<navigation>
diff --git a/appinfo/routes.php b/appinfo/routes.php
index addac33608..c54fee7967 100644
--- a/appinfo/routes.php
+++ b/appinfo/routes.php
@@ -135,6 +135,21 @@
 			'url' => '/api/providers/{providerId}/password',
 			'verb' => 'POST'
 		],
+		[
+			'name' => 'externalAccounts#indexMailboxes',
+			'url' => '/api/providers/{providerId}/mailboxes',
+			'verb' => 'GET'
+		],
+		[
+			'name' => 'externalAccounts#updateMailbox',
+			'url' => '/api/providers/{providerId}/mailboxes/{userId}',
+			'verb' => 'PUT'
+		],
+		[
+			'name' => 'externalAccounts#destroyMailbox',
+			'url' => '/api/providers/{providerId}/mailboxes/{userId}',
+			'verb' => 'DELETE'
+		],
 		[
 			'name' => 'tags#update',
 			'url' => '/api/tags/{id}',
diff --git a/composer.json b/composer.json
index 03c8fabdc5..1235d8e2d8 100644
--- a/composer.json
+++ b/composer.json
@@ -54,7 +54,7 @@
 				"source": {
 					"type": "git",
 					"url": "https://github.com/ionos-productivity/ionos-mail-configuration-api-client.git",
-					"reference": "2.0.0-20251208083401"
+					"reference": "2.0.0-20260210132735"
 				},
 				"autoload": {
 					"psr-4": {
diff --git a/composer.lock b/composer.lock
index d99348d985..5822e59de5 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "fb553591efe3fd5dbaed693076de60c6",
+    "content-hash": "be0c6c53c9b00d2b30f96797ecdc80e2",
     "packages": [
         {
             "name": "amphp/amp",
@@ -1860,7 +1860,7 @@
             "source": {
                 "type": "git",
                 "url": "https://github.com/ionos-productivity/ionos-mail-configuration-api-client.git",
-                "reference": "2.0.0-20251208083401"
+                "reference": "2.0.0-20260210132735"
             },
             "type": "library",
             "autoload": {
diff --git a/lib/Controller/ExternalAccountsController.php b/lib/Controller/ExternalAccountsController.php
index b2e968ee50..4782106979 100644
--- a/lib/Controller/ExternalAccountsController.php
+++ b/lib/Controller/ExternalAccountsController.php
@@ -248,6 +248,190 @@ public function generatePassword(string $providerId): JSONResponse {
 		}
 	}
 
+	/**
+	 * List all mailboxes for a specific provider
+	 *
+	 * @NoAdminRequired
+	 *
+	 * @param string $providerId The provider ID
+	 * @return JSONResponse
+	 */
+	#[TrapError]
+	public function indexMailboxes(string $providerId): JSONResponse {
+		try {
+			$userId = $this->getUserIdOrFail();
+
+			$this->logger->debug('Listing mailboxes for provider', [
+				'providerId' => $providerId,
+				'userId' => $userId,
+			]);
+
+			$provider = $this->providerRegistry->getProvider($providerId);
+			if ($provider === null) {
+				return MailJsonResponse::fail([
+					'error' => self::ERR_PROVIDER_NOT_FOUND,
+					'message' => 'Provider not found: ' . $providerId,
+				], Http::STATUS_NOT_FOUND);
+			}
+
+			$mailboxes = $provider->getMailboxes();
+
+			return MailJsonResponse::success(['mailboxes' => $mailboxes]);
+		} catch (\Exception $e) {
+			$this->logger->error('Error listing mailboxes', [
+				'providerId' => $providerId,
+				'exception' => $e,
+			]);
+			return MailJsonResponse::error('Could not list mailboxes');
+		}
+	}
+
+	/**
+	 * Update a mailbox (e.g., change localpart)
+	 *
+	 * @NoAdminRequired
+	 *
+	 * @param string $providerId The provider ID
+	 * @param string $userId The user ID whose mailbox to update
+	 * @return JSONResponse
+	 */
+	#[TrapError]
+	public function updateMailbox(string $providerId, string $userId): JSONResponse {
+		try {
+			$currentUserId = $this->getUserIdOrFail();
+
+			// Get update data from request
+			$data = $this->request->getParams();
+			unset($data['providerId']);
+			unset($data['userId']);
+			unset($data['_route']);
+
+			// Validate localpart if provided
+			if (isset($data['localpart'])) {
+				$localpart = trim($data['localpart']);
+				if (empty($localpart)) {
+					return MailJsonResponse::fail([
+						'error' => self::ERR_INVALID_PARAMETERS,
+						'message' => 'Localpart cannot be empty',
+					], Http::STATUS_BAD_REQUEST);
+				}
+				// Basic validation: alphanumeric, dots, hyphens, underscores
+				if (!preg_match('/^[a-zA-Z0-9._-]+$/', $localpart)) {
+					return MailJsonResponse::fail([
+						'error' => self::ERR_INVALID_PARAMETERS,
+						'message' => 'Localpart contains invalid characters',
+					], Http::STATUS_BAD_REQUEST);
+				}
+				$data['localpart'] = $localpart;
+			}
+
+			$this->logger->info('Updating mailbox', [
+				'providerId' => $providerId,
+				'userId' => $userId,
+				'currentUserId' => $currentUserId,
+				'data' => array_keys($data),
+			]);
+
+			$provider = $this->providerRegistry->getProvider($providerId);
+			if ($provider === null) {
+				return MailJsonResponse::fail([
+					'error' => self::ERR_PROVIDER_NOT_FOUND,
+					'message' => 'Provider not found: ' . $providerId,
+				], Http::STATUS_NOT_FOUND);
+			}
+
+			$mailbox = $provider->updateMailbox($userId, $data);
+
+			$this->logger->info('Mailbox updated successfully', [
+				'userId' => $userId,
+				'email' => $mailbox['email'] ?? null,
+			]);
+
+			return MailJsonResponse::success($mailbox);
+		} catch (\OCA\Mail\Exception\AccountAlreadyExistsException $e) {
+			$this->logger->warning('Email address already taken', [
+				'providerId' => $providerId,
+				'userId' => $userId,
+			]);
+			return MailJsonResponse::fail([
+				'error' => 'EMAIL_ALREADY_TAKEN',
+				'message' => 'Email is already taken',
+			], Http::STATUS_CONFLICT);
+		} catch (ServiceException $e) {
+			return $this->buildServiceErrorResponse($e, $providerId);
+		} catch (\InvalidArgumentException $e) {
+			$this->logger->error('Invalid parameters for mailbox update', [
+				'providerId' => $providerId,
+				'userId' => $userId,
+				'exception' => $e,
+			]);
+			return MailJsonResponse::fail([
+				'error' => self::ERR_INVALID_PARAMETERS,
+				'message' => $e->getMessage(),
+			], Http::STATUS_BAD_REQUEST);
+		} catch (\Exception $e) {
+			$this->logger->error('Unexpected error updating mailbox', [
+				'providerId' => $providerId,
+				'userId' => $userId,
+				'exception' => $e,
+			]);
+			return MailJsonResponse::error('Could not update mailbox');
+		}
+	}
+
+	/**
+	 * Delete a mailbox
+	 *
+	 * @NoAdminRequired
+	 *
+	 * @param string $providerId The provider ID
+	 * @param string $userId The user ID whose mailbox to delete
+	 * @return JSONResponse
+	 */
+	#[TrapError]
+	public function destroyMailbox(string $providerId, string $userId): JSONResponse {
+		try {
+			$currentUserId = $this->getUserIdOrFail();
+
+			$this->logger->info('Deleting mailbox', [
+				'providerId' => $providerId,
+				'userId' => $userId,
+				'currentUserId' => $currentUserId,
+			]);
+
+			$provider = $this->providerRegistry->getProvider($providerId);
+			if ($provider === null) {
+				return MailJsonResponse::fail([
+					'error' => self::ERR_PROVIDER_NOT_FOUND,
+					'message' => 'Provider not found: ' . $providerId,
+				], Http::STATUS_NOT_FOUND);
+			}
+
+			$success = $provider->deleteMailbox($userId);
+
+			if ($success) {
+				$this->logger->info('Mailbox deleted successfully', [
+					'userId' => $userId,
+				]);
+				return MailJsonResponse::success(['deleted' => true]);
+			} else {
+				return MailJsonResponse::fail([
+					'error' => self::ERR_SERVICE_ERROR,
+					'message' => 'Failed to delete mailbox',
+				], Http::STATUS_INTERNAL_SERVER_ERROR);
+			}
+		} catch (ServiceException $e) {
+			return $this->buildServiceErrorResponse($e, $providerId);
+		} catch (\Exception $e) {
+			$this->logger->error('Unexpected error deleting mailbox', [
+				'providerId' => $providerId,
+				'userId' => $userId,
+				'exception' => $e,
+			]);
+			return MailJsonResponse::error('Could not delete mailbox');
+		}
+	}
+
 	/**
 	 * Get the current user ID
 	 *
diff --git a/lib/Exception/AccountAlreadyExistsException.php b/lib/Exception/AccountAlreadyExistsException.php
new file mode 100644
index 0000000000..b3f45a81af
--- /dev/null
+++ b/lib/Exception/AccountAlreadyExistsException.php
@@ -0,0 +1,17 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2025 STRATO GmbH
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OCA\Mail\Exception;
+
+/**
+ * Exception thrown when attempting to create or update a mail account
+ * with an email address that already exists for another user
+ */
+class AccountAlreadyExistsException extends ServiceException {
+}
diff --git a/lib/Provider/MailAccountProvider/IMailAccountProvider.php b/lib/Provider/MailAccountProvider/IMailAccountProvider.php
index a913acba2e..bce0557da9 100644
--- a/lib/Provider/MailAccountProvider/IMailAccountProvider.php
+++ b/lib/Provider/MailAccountProvider/IMailAccountProvider.php
@@ -128,4 +128,35 @@ public function getExistingAccountEmail(string $userId): ?string;
 	 * @throws \InvalidArgumentException If provider doesn't support app passwords
 	 */
 	public function generateAppPassword(string $userId): string;
+
+	/**
+	 * Get all mailboxes managed by this provider
+	 *
+	 * Returns a list of all mailboxes (email accounts) managed by this provider
+	 * across all users. Used for administration/overview purposes.
+	 *
+	 * @return array<int, array{userId: string, email: string, name: string}> List of mailbox information
+	 * @throws \OCA\Mail\Exception\ServiceException If fetching mailboxes fails
+	 */
+	public function getMailboxes(): array;
+
+	/**
+	 * Update a mailbox (e.g., change localpart/username)
+	 *
+	 * @param string $userId The Nextcloud user ID
+	 * @param array<string, mixed> $data Update data (e.g., ['localpart' => 'newusername'])
+	 * @return array{userId: string, email: string, name: string} Updated mailbox information
+	 * @throws \OCA\Mail\Exception\AccountAlreadyExistsException If email is already taken
+	 * @throws \OCA\Mail\Exception\ServiceException If update fails
+	 */
+	public function updateMailbox(string $userId, array $data): array;
+
+	/**
+	 * Delete a mailbox
+	 *
+	 * @param string $userId The Nextcloud user ID
+	 * @return bool True if deletion was successful
+	 * @throws \OCA\Mail\Exception\ServiceException If deletion fails
+	 */
+	public function deleteMailbox(string $userId): bool;
 }
diff --git a/lib/Provider/MailAccountProvider/Implementations/Ionos/IonosProviderFacade.php b/lib/Provider/MailAccountProvider/Implementations/Ionos/IonosProviderFacade.php
index 56023407a8..ddcbae2a44 100644
--- a/lib/Provider/MailAccountProvider/Implementations/Ionos/IonosProviderFacade.php
+++ b/lib/Provider/MailAccountProvider/Implementations/Ionos/IonosProviderFacade.php
@@ -222,4 +222,91 @@ public function generateAppPassword(string $userId): string {
 
 		return $this->mutationService->resetAppPassword($userId, IonosConfigService::APP_PASSWORD_NAME_USER);
 	}
+
+	/**
+	 * Get all mailboxes managed by this provider
+	 *
+	 * Returns a list of all mailboxes (email accounts) managed by this provider
+	 * across all users. Used for administration/overview purposes.
+	 *
+	 * @return array<int, array{userId: string, email: string, name: string}> List of mailbox information
+	 */
+	public function getMailboxes(): array {
+		$this->logger->debug('Getting all IONOS mailboxes');
+		
+		try {
+			$accountResponses = $this->queryService->getAllMailAccountResponses();
+			
+			$mailboxes = [];
+			foreach ($accountResponses as $response) {
+				// Extract user ID from the email or use a placeholder
+				// The API response contains the email but we need to derive the userId
+				$email = $response->getEmail();
+				
+				// For IONOS, the email format is typically userId@domain
+				// Extract userId from the email localpart
+				$emailParts = explode('@', $email);
+				$userId = $emailParts[0] ?? '';
+				
+				$mailboxes[] = [
+					'userId' => $userId,
+					'email' => $email,
+					'name' => $response->getName() ?? $userId,
+				];
+			}
+			
+			$this->logger->debug('Retrieved IONOS mailboxes', [
+				'count' => count($mailboxes),
+			]);
+			
+			return $mailboxes;
+		} catch (\Exception $e) {
+			$this->logger->error('Error getting IONOS mailboxes', [
+				'exception' => $e,
+			]);
+			return [];
+		}
+	}
+
+	/**
+	 * Update a mailbox (e.g., change localpart)
+	 *
+	 * @param string $userId The Nextcloud user ID
+	 * @param array<string, mixed> $data Update data
+	 * @return array{userId: string, email: string, name: string} Updated mailbox information
+	 * @throws \OCA\Mail\Exception\ServiceException If update fails
+	 */
+	public function updateMailbox(string $userId, array $data): array {
+		$this->logger->info('Updating IONOS mailbox via facade', [
+			'userId' => $userId,
+			'data' => array_keys($data),
+		]);
+
+		$localpart = $data['localpart'] ?? null;
+		$name = $data['name'] ?? '';
+
+		if ($localpart === null || $localpart === '') {
+			throw new \InvalidArgumentException('localpart is required for mailbox update');
+		}
+
+		// Update the account using the creation service (which handles updates)
+		$account = $this->creationService->createOrUpdateAccount($userId, $localpart, $name);
+
+		return [
+			'userId' => $userId,
+			'email' => $account->getEmail(),
+			'name' => $account->getName(),
+		];
+	}
+
+	/**
+	 * Delete a mailbox
+	 *
+	 * @param string $userId The Nextcloud user ID
+	 * @return bool True if deletion was successful
+	 * @throws \OCA\Mail\Exception\ServiceException If deletion fails
+	 */
+	public function deleteMailbox(string $userId): bool {
+		return $this->deleteAccount($userId);
+	}
 }
diff --git a/lib/Provider/MailAccountProvider/Implementations/Ionos/Service/Core/IonosAccountMutationService.php b/lib/Provider/MailAccountProvider/Implementations/Ionos/Service/Core/IonosAccountMutationService.php
index 475efca764..0f7d8d1204 100644
--- a/lib/Provider/MailAccountProvider/Implementations/Ionos/Service/Core/IonosAccountMutationService.php
+++ b/lib/Provider/MailAccountProvider/Implementations/Ionos/Service/Core/IonosAccountMutationService.php
@@ -10,11 +10,11 @@
 namespace OCA\Mail\Provider\MailAccountProvider\Implementations\Ionos\Service\Core;
 
 use IONOS\MailConfigurationAPI\Client\ApiException;
-use IONOS\MailConfigurationAPI\Client\Model\Imap;
+use IONOS\MailConfigurationAPI\Client\Model\ImapConfig;
 use IONOS\MailConfigurationAPI\Client\Model\MailAccountCreatedResponse;
 use IONOS\MailConfigurationAPI\Client\Model\MailAddonErrorMessage;
 use IONOS\MailConfigurationAPI\Client\Model\MailCreateData;
-use IONOS\MailConfigurationAPI\Client\Model\Smtp;
+use IONOS\MailConfigurationAPI\Client\Model\SmtpConfig;
 use OCA\Mail\Exception\ServiceException;
 use OCA\Mail\Provider\MailAccountProvider\Common\Dto\MailAccountConfig;
 use OCA\Mail\Provider\MailAccountProvider\Common\Dto\MailServerConfig;
@@ -356,13 +356,13 @@ private function buildSuccessResponse(MailAccountCreatedResponse $response): Mai
 	 * Creates a complete MailAccountConfig object by combining IMAP and SMTP server
 	 * configurations with email credentials. SSL modes are normalized to standard format.
 	 *
-	 * @param Imap $imapServer IMAP server configuration object
-	 * @param Smtp $smtpServer SMTP server configuration object
+	 * @param ImapConfig $imapServer IMAP server configuration object
+	 * @param SmtpConfig $smtpServer SMTP server configuration object
 	 * @param string $email Email address
 	 * @param string $password Account password
 	 * @return MailAccountConfig Complete mail account configuration
 	 */
-	private function buildMailAccountConfig(Imap $imapServer, Smtp $smtpServer, string $email, string $password): MailAccountConfig {
+	private function buildMailAccountConfig(ImapConfig $imapServer, SmtpConfig $smtpServer, string $email, string $password): MailAccountConfig {
 		$imapConfig = new MailServerConfig(
 			host: $imapServer->getHost(),
 			port: $imapServer->getPort(),
diff --git a/lib/Provider/MailAccountProvider/Implementations/Ionos/Service/Core/IonosAccountQueryService.php b/lib/Provider/MailAccountProvider/Implementations/Ionos/Service/Core/IonosAccountQueryService.php
index 219f27f818..9e782ea480 100644
--- a/lib/Provider/MailAccountProvider/Implementations/Ionos/Service/Core/IonosAccountQueryService.php
+++ b/lib/Provider/MailAccountProvider/Implementations/Ionos/Service/Core/IonosAccountQueryService.php
@@ -182,6 +182,45 @@ public function getMailDomain(): string {
 		return $this->configService->getMailDomain();
 	}
 
+	/**
+	 * Get all IONOS mail accounts
+	 *
+	 * @return array<int, MailAccountResponse> List of mail account responses
+	 */
+	public function getAllMailAccountResponses(): array {
+		try {
+			$this->logger->debug('Getting all IONOS mail accounts', [
+				'extRef' => $this->configService->getExternalReference(),
+			]);
+
+			$apiInstance = $this->createApiInstance();
+			$result = $apiInstance->getAllFunctionalAccounts(
+				self::BRAND,
+				$this->configService->getExternalReference()
+			);
+
+			if (is_array($result)) {
+				$this->logger->debug('Retrieved IONOS mail accounts', [
+					'count' => count($result),
+				]);
+				return $result;
+			}
+
+			return [];
+		} catch (ApiException $e) {
+			$this->logger->error('API error getting all IONOS mail accounts', [
+				'statusCode' => $e->getCode(),
+				'error' => $e->getMessage(),
+			]);
+			return [];
+		} catch (\Exception $e) {
+			$this->logger->error('Unexpected error getting all IONOS mail accounts', [
+				'error' => $e->getMessage(),
+			]);
+			return [];
+		}
+	}
+
 	/**
 	 * Get the current user ID from the session
 	 *
diff --git a/lib/Provider/MailAccountProvider/Implementations/Ionos/Service/IonosMailService.php b/lib/Provider/MailAccountProvider/Implementations/Ionos/Service/IonosMailService.php
index 69f31cd278..1a5d7a37d8 100644
--- a/lib/Provider/MailAccountProvider/Implementations/Ionos/Service/IonosMailService.php
+++ b/lib/Provider/MailAccountProvider/Implementations/Ionos/Service/IonosMailService.php
@@ -11,12 +11,12 @@
 
 use IONOS\MailConfigurationAPI\Client\Api\MailConfigurationAPIApi;
 use IONOS\MailConfigurationAPI\Client\ApiException;
-use IONOS\MailConfigurationAPI\Client\Model\Imap;
+use IONOS\MailConfigurationAPI\Client\Model\ImapConfig;
 use IONOS\MailConfigurationAPI\Client\Model\MailAccountCreatedResponse;
 use IONOS\MailConfigurationAPI\Client\Model\MailAccountResponse;
 use IONOS\MailConfigurationAPI\Client\Model\MailAddonErrorMessage;
 use IONOS\MailConfigurationAPI\Client\Model\MailCreateData;
-use IONOS\MailConfigurationAPI\Client\Model\Smtp;
+use IONOS\MailConfigurationAPI\Client\Model\SmtpConfig;
 use OCA\Mail\Exception\ServiceException;
 use OCA\Mail\Provider\MailAccountProvider\Common\Dto\MailAccountConfig;
 use OCA\Mail\Provider\MailAccountProvider\Common\Dto\MailServerConfig;
@@ -333,13 +333,13 @@ private function buildSuccessResponse(MailAccountCreatedResponse $response): Mai
 	/**
 	 * Build mail account configuration from server details
 	 *
-	 * @param Imap $imapServer IMAP server configuration object
-	 * @param Smtp $smtpServer SMTP server configuration object
+	 * @param ImapConfig $imapServer IMAP server configuration object
+	 * @param SmtpConfig $smtpServer SMTP server configuration object
 	 * @param string $email Email address
 	 * @param string $password Account password
 	 * @return MailAccountConfig Complete mail account configuration
 	 */
-	private function buildMailAccountConfig(Imap $imapServer, Smtp $smtpServer, string $email, string $password): MailAccountConfig {
+	private function buildMailAccountConfig(ImapConfig $imapServer, SmtpConfig $smtpServer, string $email, string $password): MailAccountConfig {
 		$imapConfig = new MailServerConfig(
 			host: $imapServer->getHost(),
 			port: $imapServer->getPort(),
diff --git a/lib/Provider/MailAccountProvider/Implementations/IonosProvider.php b/lib/Provider/MailAccountProvider/Implementations/IonosProvider.php
index 46e2b6f6b2..f2f9a839c7 100644
--- a/lib/Provider/MailAccountProvider/Implementations/IonosProvider.php
+++ b/lib/Provider/MailAccountProvider/Implementations/IonosProvider.php
@@ -156,4 +156,16 @@ public function generateAppPassword(string $userId): string {
 			);
 		}
 	}
+
+	public function getMailboxes(): array {
+		return $this->facade->getMailboxes();
+	}
+
+	public function updateMailbox(string $userId, array $data): array {
+		return $this->facade->updateMailbox($userId, $data);
+	}
+
+	public function deleteMailbox(string $userId): bool {
+		return $this->facade->deleteMailbox($userId);
+	}
 }
diff --git a/lib/Settings/ProviderAccountOverviewSettings.php b/lib/Settings/ProviderAccountOverviewSettings.php
new file mode 100644
index 0000000000..0e6253e742
--- /dev/null
+++ b/lib/Settings/ProviderAccountOverviewSettings.php
@@ -0,0 +1,44 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2025 STRATO GmbH
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OCA\Mail\Settings;
+
+use OCA\Mail\AppInfo\Application;
+use OCP\AppFramework\Http\TemplateResponse;
+use OCP\Settings\IDelegatedSettings;
+
+/**
+ * Settings for provider account overview and management
+ */
+class ProviderAccountOverviewSettings implements IDelegatedSettings {
+	#[\Override]
+	public function getForm() {
+		return new TemplateResponse(Application::APP_ID, 'settings-provider-account-overview');
+	}
+
+	#[\Override]
+	public function getSection() {
+		return 'mail-provider-accounts';
+	}
+
+	#[\Override]
+	public function getPriority() {
+		return 50;
+	}
+
+	#[\Override]
+	public function getName(): ?string {
+		return null;
+	}
+
+	#[\Override]
+	public function getAuthorizedAppConfig(): array {
+		return [];
+	}
+}
diff --git a/lib/Settings/Section/MailProviderAccountsSection.php b/lib/Settings/Section/MailProviderAccountsSection.php
new file mode 100644
index 0000000000..e7ddb3ce84
--- /dev/null
+++ b/lib/Settings/Section/MailProviderAccountsSection.php
@@ -0,0 +1,45 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2025 STRATO GmbH
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OCA\Mail\Settings\Section;
+
+use OCP\IL10N;
+use OCP\IURLGenerator;
+use OCP\Settings\IIconSection;
+
+/**
+ * Section for mail provider account administration
+ */
+class MailProviderAccountsSection implements IIconSection {
+	public function __construct(
+		private IL10N $l,
+		private IURLGenerator $urlGenerator,
+	) {
+	}
+
+	#[\Override]
+	public function getID(): string {
+		return 'mail-provider-accounts';
+	}
+
+	#[\Override]
+	public function getName(): string {
+		return $this->l->t('Email Provider Accounts');
+	}
+
+	#[\Override]
+	public function getPriority(): int {
+		return 55;
+	}
+
+	#[\Override]
+	public function getIcon(): string {
+		return $this->urlGenerator->imagePath('mail', 'mail.svg');
+	}
+}
diff --git a/src/components/mailboxAdmin/MailboxAdministration.vue b/src/components/mailboxAdmin/MailboxAdministration.vue
new file mode 100644
index 0000000000..cf4e2fe67e
--- /dev/null
+++ b/src/components/mailboxAdmin/MailboxAdministration.vue
@@ -0,0 +1,225 @@
+<!--
+  - SPDX-FileCopyrightText: 2025 STRATO GmbH
+  - SPDX-License-Identifier: AGPL-3.0-or-later
+-->
+
+<template>
+	<SettingsSection :name="t('mail', 'Email Administration')"
+		:description="t('mail', 'Manage email accounts for your users')">
+		<div class="mailbox-administration">
+			<h3>{{ t('mail', 'Manage Emails') }}</h3>
+
+			<!-- Loading state -->
+			<div v-if="loading" class="loading-container">
+				<NcLoadingIcon :size="32" />
+				<p>{{ t('mail', 'Loading mailboxes...') }}</p>
+			</div>
+
+			<!-- Error state -->
+			<NcNoteCard v-else-if="error" type="error">
+				{{ error }}
+			</NcNoteCard>
+
+			<!-- Empty state -->
+			<NcEmptyContent v-else-if="mailboxes.length === 0"
+				:name="t('mail', 'No mailboxes found')"
+				:description="t('mail', 'There are no mailboxes to display.')">
+				<template #icon>
+					<IconMail :size="64" />
+				</template>
+			</NcEmptyContent>
+
+			<!-- Mailbox list -->
+			<div v-else class="mailbox-list">
+				<table class="mailbox-table">
+					<thead>
+						<tr>
+							<th>{{ t('mail', 'Email Address') }}</th>
+							<th>{{ t('mail', 'Linked User') }}</th>
+							<th class="actions-column">{{ t('mail', 'Actions') }}</th>
+						</tr>
+					</thead>
+					<tbody>
+						<MailboxListItem v-for="mailbox in mailboxes"
+							:key="mailbox.userId"
+							:mailbox="mailbox"
+							@edit="handleEdit"
+							@delete="handleDelete" />
+					</tbody>
+				</table>
+			</div>
+
+			<!-- Deletion modal -->
+			<MailboxDeletionModal v-if="showDeleteModal"
+				:mailbox="selectedMailbox"
+				@confirm="confirmDelete"
+				@cancel="cancelDelete" />
+		</div>
+	</SettingsSection>
+</template>
+
+<script>
+import { NcEmptyContent, NcLoadingIcon, NcNoteCard, NcSettingsSection as SettingsSection } from '@nextcloud/vue'
+import IconMail from 'vue-material-design-icons/Email.vue'
+
+import MailboxListItem from './MailboxListItem.vue'
+import MailboxDeletionModal from './MailboxDeletionModal.vue'
+import { getMailboxes, getProviders, deleteMailbox } from '../../service/MailboxAdminService.js'
+import { showError, showSuccess } from '@nextcloud/dialogs'
+
+export default {
+	name: 'MailboxAdministration',
+	components: {
+		SettingsSection,
+		NcEmptyContent,
+		NcLoadingIcon,
+		NcNoteCard,
+		IconMail,
+		MailboxListItem,
+		MailboxDeletionModal,
+	},
+	data() {
+		return {
+			loading: false,
+			error: null,
+			mailboxes: [],
+			providers: [],
+			showDeleteModal: false,
+			selectedMailbox: null,
+		}
+	},
+	async mounted() {
+		await this.loadProviders()
+		await this.loadMailboxes()
+	},
+	methods: {
+		async loadProviders() {
+			try {
+				const response = await getProviders()
+				this.providers = response.data?.providers || []
+			} catch (error) {
+				console.error('Failed to load providers', error)
+				this.error = this.t('mail', 'Failed to load providers')
+			}
+		},
+		async loadMailboxes() {
+			this.loading = true
+			this.error = null
+
+			try {
+				// For now, we'll load from the first provider
+				// In a real scenario, you might want to load from all providers
+				if (this.providers.length === 0) {
+					this.mailboxes = []
+					return
+				}
+
+				const providerId = this.providers[0].id
+				const response = await getMailboxes(providerId)
+				this.mailboxes = response.data?.mailboxes || []
+			} catch (error) {
+				console.error('Failed to load mailboxes', error)
+				this.error = this.t('mail', 'Failed to load mailboxes')
+			} finally {
+				this.loading = false
+			}
+		},
+		handleEdit(mailbox) {
+			// TODO: Implement edit functionality
+			console.log('Edit mailbox', mailbox)
+			showError(this.t('mail', 'Edit functionality not yet implemented'))
+		},
+		handleDelete(mailbox) {
+			this.selectedMailbox = mailbox
+			this.showDeleteModal = true
+		},
+		async confirmDelete() {
+			if (!this.selectedMailbox) {
+				return
+			}
+
+			try {
+				const providerId = this.providers[0].id
+				await deleteMailbox(providerId, this.selectedMailbox.userId)
+				
+				showSuccess(this.t('mail', 'Mailbox deleted successfully'))
+				
+				// Remove from list
+				this.mailboxes = this.mailboxes.filter(
+					m => m.userId !== this.selectedMailbox.userId
+				)
+			} catch (error) {
+				console.error('Failed to delete mailbox', error)
+				const errorMsg = error.response?.data?.data?.message || this.t('mail', 'Failed to delete mailbox')
+				showError(errorMsg)
+			} finally {
+				this.cancelDelete()
+			}
+		},
+		cancelDelete() {
+			this.showDeleteModal = false
+			this.selectedMailbox = null
+		},
+	},
+}
+</script>
+
+<style scoped lang="scss">
+.mailbox-administration {
+	padding: 20px 0;
+
+	h3 {
+		margin-bottom: 20px;
+		font-weight: 600;
+		font-size: 18px;
+	}
+
+	.loading-container {
+		display: flex;
+		flex-direction: column;
+		align-items: center;
+		justify-content: center;
+		padding: 40px 0;
+		gap: 16px;
+
+		p {
+			color: var(--color-text-lighter);
+		}
+	}
+
+	.mailbox-list {
+		margin-top: 20px;
+	}
+
+	.mailbox-table {
+		width: 100%;
+		border-collapse: collapse;
+
+		thead {
+			background-color: var(--color-background-dark);
+
+			th {
+				text-align: left;
+				padding: 12px;
+				font-weight: 600;
+				border-bottom: 2px solid var(--color-border);
+
+				&.actions-column {
+					text-align: right;
+					width: 120px;
+				}
+			}
+		}
+
+		tbody {
+			tr {
+				border-bottom: 1px solid var(--color-border);
+
+				&:hover {
+					background-color: var(--color-background-hover);
+				}
+			}
+		}
+	}
+}
+</style>
diff --git a/src/components/mailboxAdmin/MailboxDeletionModal.vue b/src/components/mailboxAdmin/MailboxDeletionModal.vue
new file mode 100644
index 0000000000..f3ae402990
--- /dev/null
+++ b/src/components/mailboxAdmin/MailboxDeletionModal.vue
@@ -0,0 +1,118 @@
+<!--
+  - SPDX-FileCopyrightText: 2025 STRATO GmbH
+  - SPDX-License-Identifier: AGPL-3.0-or-later
+-->
+
+<template>
+	<NcDialog :name="t('mail', 'Mailbox deletion')"
+		:open="true"
+		@update:open="handleClose">
+		<div class="deletion-modal-content">
+			<NcNoteCard type="warning">
+				<p>
+					{{
+						t(
+							'mail',
+							'Are you sure you want to delete the mailbox for {email}?',
+							{ email: mailbox?.email || '' }
+						)
+					}}
+				</p>
+				<p class="warning-text">
+					{{ t('mail', 'This action cannot be undone. All emails and settings for this account will be permanently deleted.') }}
+				</p>
+			</NcNoteCard>
+
+			<div class="mailbox-details">
+				<div class="detail-row">
+					<span class="label">{{ t('mail', 'Email Address:') }}</span>
+					<span class="value">{{ mailbox?.email || '' }}</span>
+				</div>
+				<div class="detail-row">
+					<span class="label">{{ t('mail', 'User:') }}</span>
+					<span class="value">{{ mailbox?.name || mailbox?.userId || '' }}</span>
+				</div>
+			</div>
+		</div>
+
+		<template #actions>
+			<NcButton type="secondary" @click="handleClose">
+				{{ t('mail', 'Cancel') }}
+			</NcButton>
+			<NcButton type="error" @click="handleConfirm">
+				<template #icon>
+					<IconDelete :size="20" />
+				</template>
+				{{ t('mail', 'Delete mailbox') }}
+			</NcButton>
+		</template>
+	</NcDialog>
+</template>
+
+<script>
+import { NcDialog, NcButton, NcNoteCard } from '@nextcloud/vue'
+import IconDelete from 'vue-material-design-icons/Delete.vue'
+
+export default {
+	name: 'MailboxDeletionModal',
+	components: {
+		NcDialog,
+		NcButton,
+		NcNoteCard,
+		IconDelete,
+	},
+	props: {
+		mailbox: {
+			type: Object,
+			default: null,
+		},
+	},
+	emits: ['confirm', 'cancel'],
+	methods: {
+		handleConfirm() {
+			this.$emit('confirm')
+		},
+		handleClose() {
+			this.$emit('cancel')
+		},
+	},
+}
+</script>
+
+<style scoped lang="scss">
+.deletion-modal-content {
+	padding: 16px 0;
+
+	.warning-text {
+		margin-top: 12px;
+		font-weight: 500;
+		color: var(--color-error);
+	}
+
+	.mailbox-details {
+		margin-top: 20px;
+		padding: 16px;
+		background-color: var(--color-background-dark);
+		border-radius: var(--border-radius);
+
+		.detail-row {
+			display: flex;
+			gap: 12px;
+			margin-bottom: 8px;
+
+			&:last-child {
+				margin-bottom: 0;
+			}
+
+			.label {
+				font-weight: 600;
+				min-width: 120px;
+			}
+
+			.value {
+				color: var(--color-text-lighter);
+			}
+		}
+	}
+}
+</style>
diff --git a/src/components/mailboxAdmin/MailboxListItem.vue b/src/components/mailboxAdmin/MailboxListItem.vue
new file mode 100644
index 0000000000..f4b48b39ac
--- /dev/null
+++ b/src/components/mailboxAdmin/MailboxListItem.vue
@@ -0,0 +1,114 @@
+<!--
+  - SPDX-FileCopyrightText: 2025 STRATO GmbH
+  - SPDX-License-Identifier: AGPL-3.0-or-later
+-->
+
+<template>
+	<tr class="mailbox-list-item">
+		<td class="email-column">
+			<span class="email-address">{{ mailbox.email }}</span>
+		</td>
+		<td class="user-column">
+			<div class="user-info">
+				<NcAvatar :user="mailbox.userId"
+					:size="32"
+					:display-name="mailbox.name || mailbox.userId" />
+				<div class="user-details">
+					<span class="user-name">{{ mailbox.name || mailbox.userId }}</span>
+					<span class="user-id">{{ mailbox.userId }}</span>
+				</div>
+			</div>
+		</td>
+		<td class="actions-column">
+			<div class="actions">
+				<NcActions>
+					<NcActionButton @click="$emit('edit', mailbox)">
+						<template #icon>
+							<IconPencil :size="20" />
+						</template>
+						{{ t('mail', 'Edit') }}
+					</NcActionButton>
+					<NcActionButton @click="$emit('delete', mailbox)">
+						<template #icon>
+							<IconDelete :size="20" />
+						</template>
+						{{ t('mail', 'Delete') }}
+					</NcActionButton>
+				</NcActions>
+			</div>
+		</td>
+	</tr>
+</template>
+
+<script>
+import { NcAvatar, NcActions, NcActionButton } from '@nextcloud/vue'
+import IconPencil from 'vue-material-design-icons/Pencil.vue'
+import IconDelete from 'vue-material-design-icons/Delete.vue'
+
+export default {
+	name: 'MailboxListItem',
+	components: {
+		NcAvatar,
+		NcActions,
+		NcActionButton,
+		IconPencil,
+		IconDelete,
+	},
+	props: {
+		mailbox: {
+			type: Object,
+			required: true,
+		},
+	},
+	emits: ['edit', 'delete'],
+}
+</script>
+
+<style scoped lang="scss">
+.mailbox-list-item {
+	td {
+		padding: 12px;
+		vertical-align: middle;
+	}
+
+	.email-column {
+		.email-address {
+			font-family: monospace;
+			font-size: 14px;
+		}
+	}
+
+	.user-column {
+		.user-info {
+			display: flex;
+			align-items: center;
+			gap: 12px;
+
+			.user-details {
+				display: flex;
+				flex-direction: column;
+				gap: 2px;
+
+				.user-name {
+					font-weight: 500;
+					font-size: 14px;
+				}
+
+				.user-id {
+					font-size: 12px;
+					color: var(--color-text-lighter);
+				}
+			}
+		}
+	}
+
+	.actions-column {
+		text-align: right;
+
+		.actions {
+			display: flex;
+			justify-content: flex-end;
+		}
+	}
+}
+</style>
diff --git a/src/main-provider-account-overview.js b/src/main-provider-account-overview.js
new file mode 100644
index 0000000000..4ca7fc828e
--- /dev/null
+++ b/src/main-provider-account-overview.js
@@ -0,0 +1,22 @@
+/**
+ * SPDX-FileCopyrightText: 2025 STRATO GmbH
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+import { generateFilePath } from '@nextcloud/router'
+import { getRequestToken } from '@nextcloud/auth'
+import '@nextcloud/dialogs/style.css'
+import Vue from 'vue'
+
+import MailboxAdministration from './components/mailboxAdmin/MailboxAdministration.vue'
+import Nextcloud from './mixins/Nextcloud.js'
+
+// eslint-disable-next-line camelcase
+__webpack_nonce__ = btoa(getRequestToken())
+// eslint-disable-next-line camelcase
+__webpack_public_path__ = generateFilePath('mail', '', 'js/')
+
+Vue.mixin(Nextcloud)
+
+const View = Vue.extend(MailboxAdministration)
+new View().$mount('#mail-provider-account-overview')
diff --git a/src/service/MailboxAdminService.js b/src/service/MailboxAdminService.js
new file mode 100644
index 0000000000..ce8d097e7b
--- /dev/null
+++ b/src/service/MailboxAdminService.js
@@ -0,0 +1,61 @@
+/**
+ * SPDX-FileCopyrightText: 2025 STRATO GmbH
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+import axios from '@nextcloud/axios'
+import { generateUrl } from '@nextcloud/router'
+
+/**
+ * Get all mailboxes for a provider
+ *
+ * @param {string} providerId The provider ID
+ * @return {Promise}
+ */
+export const getMailboxes = (providerId) => {
+	const url = generateUrl('/apps/mail/api/providers/{providerId}/mailboxes', {
+		providerId,
+	})
+	return axios.get(url).then((resp) => resp.data)
+}
+
+/**
+ * Update a mailbox
+ *
+ * @param {string} providerId The provider ID
+ * @param {string} userId The user ID
+ * @param {object} data Update data (localpart, name, etc.)
+ * @return {Promise}
+ */
+export const updateMailbox = (providerId, userId, data) => {
+	const url = generateUrl('/apps/mail/api/providers/{providerId}/mailboxes/{userId}', {
+		providerId,
+		userId,
+	})
+	return axios.put(url, data).then((resp) => resp.data)
+}
+
+/**
+ * Delete a mailbox
+ *
+ * @param {string} providerId The provider ID
+ * @param {string} userId The user ID
+ * @return {Promise}
+ */
+export const deleteMailbox = (providerId, userId) => {
+	const url = generateUrl('/apps/mail/api/providers/{providerId}/mailboxes/{userId}', {
+		providerId,
+		userId,
+	})
+	return axios.delete(url).then((resp) => resp.data)
+}
+
+/**
+ * Get available providers
+ *
+ * @return {Promise}
+ */
+export const getProviders = () => {
+	const url = generateUrl('/apps/mail/api/providers')
+	return axios.get(url).then((resp) => resp.data)
+}
diff --git a/templates/settings-provider-account-overview.php b/templates/settings-provider-account-overview.php
new file mode 100644
index 0000000000..4f3ab1919f
--- /dev/null
+++ b/templates/settings-provider-account-overview.php
@@ -0,0 +1,12 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2025 STRATO GmbH
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+script(\OCA\Mail\AppInfo\Application::APP_ID, 'provider-account-overview');
+
+?>
+<div id="mail-provider-account-overview">
+</div>
diff --git a/tests/Unit/Controller/ExternalAccountsControllerTest.php b/tests/Unit/Controller/ExternalAccountsControllerTest.php
index 3c29745ba4..72feea8299 100644
--- a/tests/Unit/Controller/ExternalAccountsControllerTest.php
+++ b/tests/Unit/Controller/ExternalAccountsControllerTest.php
@@ -599,4 +599,247 @@ public function testGeneratePasswordWithServiceException(): void {
 		$this->assertEquals('fail', $data['status']);
 		$this->assertEquals('SERVICE_ERROR', $data['data']['error']);
 	}
+
+	// Mailbox management tests
+
+	public function testIndexMailboxesSuccess(): void {
+		$user = $this->createMock(IUser::class);
+		$user->method('getUID')->willReturn('testuser');
+
+		$this->userSession->method('getUser')
+			->willReturn($user);
+
+		$mailboxes = [
+			['userId' => 'user1', 'email' => 'user1@example.com', 'name' => 'User One'],
+			['userId' => 'user2', 'email' => 'user2@example.com', 'name' => 'User Two'],
+		];
+
+		$provider = $this->createMock(IMailAccountProvider::class);
+		$provider->method('getMailboxes')
+			->willReturn($mailboxes);
+
+		$this->providerRegistry->method('getProvider')
+			->with('test-provider')
+			->willReturn($provider);
+
+		$response = $this->controller->indexMailboxes('test-provider');
+
+		$this->assertEquals(Http::STATUS_OK, $response->getStatus());
+		$data = $response->getData();
+		$this->assertEquals('success', $data['status']);
+		$this->assertEquals($mailboxes, $data['data']['mailboxes']);
+	}
+
+	public function testIndexMailboxesWithProviderNotFound(): void {
+		$user = $this->createMock(IUser::class);
+		$user->method('getUID')->willReturn('testuser');
+
+		$this->userSession->method('getUser')
+			->willReturn($user);
+
+		$this->providerRegistry->method('getProvider')
+			->with('nonexistent')
+			->willReturn(null);
+
+		$response = $this->controller->indexMailboxes('nonexistent');
+
+		$this->assertEquals(Http::STATUS_NOT_FOUND, $response->getStatus());
+		$data = $response->getData();
+		$this->assertEquals('fail', $data['status']);
+		$this->assertEquals('PROVIDER_NOT_FOUND', $data['data']['error']);
+	}
+
+	public function testUpdateMailboxSuccess(): void {
+		$user = $this->createMock(IUser::class);
+		$user->method('getUID')->willReturn('testuser');
+
+		$this->userSession->method('getUser')
+			->willReturn($user);
+
+		$this->request->method('getParams')
+			->willReturn([
+				'providerId' => 'test-provider',
+				'userId' => 'targetuser',
+				'_route' => 'some-route',
+				'localpart' => 'newusername',
+				'name' => 'New Name',
+			]);
+
+		$updatedMailbox = [
+			'userId' => 'targetuser',
+			'email' => 'newusername@example.com',
+			'name' => 'New Name',
+		];
+
+		$provider = $this->createMock(IMailAccountProvider::class);
+		$provider->method('updateMailbox')
+			->with('targetuser', ['localpart' => 'newusername', 'name' => 'New Name'])
+			->willReturn($updatedMailbox);
+
+		$this->providerRegistry->method('getProvider')
+			->with('test-provider')
+			->willReturn($provider);
+
+		$response = $this->controller->updateMailbox('test-provider', 'targetuser');
+
+		$this->assertEquals(Http::STATUS_OK, $response->getStatus());
+		$data = $response->getData();
+		$this->assertEquals('success', $data['status']);
+		$this->assertEquals($updatedMailbox, $data['data']);
+	}
+
+	public function testUpdateMailboxWithInvalidLocalpart(): void {
+		$user = $this->createMock(IUser::class);
+		$user->method('getUID')->willReturn('testuser');
+
+		$this->userSession->method('getUser')
+			->willReturn($user);
+
+		$this->request->method('getParams')
+			->willReturn([
+				'providerId' => 'test-provider',
+				'userId' => 'targetuser',
+				'_route' => 'some-route',
+				'localpart' => 'invalid@user', // Contains invalid character @
+			]);
+
+		$this->providerRegistry->method('getProvider')
+			->with('test-provider')
+			->willReturn($this->createMock(IMailAccountProvider::class));
+
+		$response = $this->controller->updateMailbox('test-provider', 'targetuser');
+
+		$this->assertEquals(Http::STATUS_BAD_REQUEST, $response->getStatus());
+		$data = $response->getData();
+		$this->assertEquals('fail', $data['status']);
+		$this->assertEquals('INVALID_PARAMETERS', $data['data']['error']);
+		$this->assertStringContainsString('invalid characters', $data['data']['message']);
+	}
+
+	public function testUpdateMailboxWithEmptyLocalpart(): void {
+		$user = $this->createMock(IUser::class);
+		$user->method('getUID')->willReturn('testuser');
+
+		$this->userSession->method('getUser')
+			->willReturn($user);
+
+		$this->request->method('getParams')
+			->willReturn([
+				'providerId' => 'test-provider',
+				'userId' => 'targetuser',
+				'_route' => 'some-route',
+				'localpart' => '   ', // Empty after trim
+			]);
+
+		$this->providerRegistry->method('getProvider')
+			->with('test-provider')
+			->willReturn($this->createMock(IMailAccountProvider::class));
+
+		$response = $this->controller->updateMailbox('test-provider', 'targetuser');
+
+		$this->assertEquals(Http::STATUS_BAD_REQUEST, $response->getStatus());
+		$data = $response->getData();
+		$this->assertEquals('fail', $data['status']);
+		$this->assertEquals('INVALID_PARAMETERS', $data['data']['error']);
+		$this->assertStringContainsString('cannot be empty', $data['data']['message']);
+	}
+
+	public function testUpdateMailboxWithAccountAlreadyExistsException(): void {
+		$user = $this->createMock(IUser::class);
+		$user->method('getUID')->willReturn('testuser');
+
+		$this->userSession->method('getUser')
+			->willReturn($user);
+
+		$this->request->method('getParams')
+			->willReturn([
+				'providerId' => 'test-provider',
+				'userId' => 'targetuser',
+				'_route' => 'some-route',
+				'localpart' => 'existinguser',
+			]);
+
+		$provider = $this->createMock(IMailAccountProvider::class);
+		$provider->method('updateMailbox')
+			->willThrowException(new \OCA\Mail\Exception\AccountAlreadyExistsException('Email already taken'));
+
+		$this->providerRegistry->method('getProvider')
+			->with('test-provider')
+			->willReturn($provider);
+
+		$response = $this->controller->updateMailbox('test-provider', 'targetuser');
+
+		$this->assertEquals(Http::STATUS_CONFLICT, $response->getStatus());
+		$data = $response->getData();
+		$this->assertEquals('fail', $data['status']);
+		$this->assertEquals('EMAIL_ALREADY_TAKEN', $data['data']['error']);
+		$this->assertEquals('Email is already taken', $data['data']['message']);
+	}
+
+	public function testDestroyMailboxSuccess(): void {
+		$user = $this->createMock(IUser::class);
+		$user->method('getUID')->willReturn('testuser');
+
+		$this->userSession->method('getUser')
+			->willReturn($user);
+
+		$provider = $this->createMock(IMailAccountProvider::class);
+		$provider->method('deleteMailbox')
+			->with('targetuser')
+			->willReturn(true);
+
+		$this->providerRegistry->method('getProvider')
+			->with('test-provider')
+			->willReturn($provider);
+
+		$response = $this->controller->destroyMailbox('test-provider', 'targetuser');
+
+		$this->assertEquals(Http::STATUS_OK, $response->getStatus());
+		$data = $response->getData();
+		$this->assertEquals('success', $data['status']);
+		$this->assertTrue($data['data']['deleted']);
+	}
+
+	public function testDestroyMailboxWithProviderNotFound(): void {
+		$user = $this->createMock(IUser::class);
+		$user->method('getUID')->willReturn('testuser');
+
+		$this->userSession->method('getUser')
+			->willReturn($user);
+
+		$this->providerRegistry->method('getProvider')
+			->with('nonexistent')
+			->willReturn(null);
+
+		$response = $this->controller->destroyMailbox('nonexistent', 'targetuser');
+
+		$this->assertEquals(Http::STATUS_NOT_FOUND, $response->getStatus());
+		$data = $response->getData();
+		$this->assertEquals('fail', $data['status']);
+		$this->assertEquals('PROVIDER_NOT_FOUND', $data['data']['error']);
+	}
+
+	public function testDestroyMailboxFailed(): void {
+		$user = $this->createMock(IUser::class);
+		$user->method('getUID')->willReturn('testuser');
+
+		$this->userSession->method('getUser')
+			->willReturn($user);
+
+		$provider = $this->createMock(IMailAccountProvider::class);
+		$provider->method('deleteMailbox')
+			->with('targetuser')
+			->willReturn(false);
+
+		$this->providerRegistry->method('getProvider')
+			->with('test-provider')
+			->willReturn($provider);
+
+		$response = $this->controller->destroyMailbox('test-provider', 'targetuser');
+
+		$this->assertEquals(Http::STATUS_INTERNAL_SERVER_ERROR, $response->getStatus());
+		$data = $response->getData();
+		$this->assertEquals('fail', $data['status']);
+		$this->assertEquals('SERVICE_ERROR', $data['data']['error']);
+	}
 }
diff --git a/tests/Unit/Provider/MailAccountProvider/Implementations/Ionos/IonosProviderFacadeTest.php b/tests/Unit/Provider/MailAccountProvider/Implementations/Ionos/IonosProviderFacadeTest.php
index 2d064ae009..6d907a0df6 100644
--- a/tests/Unit/Provider/MailAccountProvider/Implementations/Ionos/IonosProviderFacadeTest.php
+++ b/tests/Unit/Provider/MailAccountProvider/Implementations/Ionos/IonosProviderFacadeTest.php
@@ -386,4 +386,89 @@ public function testGenerateAppPasswordThrowsException(): void {
 
 		$this->facade->generateAppPassword($userId);
 	}
+
+	public function testGetMailboxesReturnsEmptyArrayWhenNoAccounts(): void {
+		$this->logger->expects($this->once())
+			->method('debug')
+			->with('Getting all IONOS mailboxes');
+
+		$this->queryService->expects($this->once())
+			->method('getAllMailAccountResponses')
+			->willReturn([]);
+
+		$result = $this->facade->getMailboxes();
+
+		$this->assertIsArray($result);
+		$this->assertEmpty($result);
+	}
+
+	public function testGetMailboxesReturnsMailboxList(): void {
+		$mockResponse1 = $this->createMock(\IONOS\MailConfigurationAPI\Client\Model\MailAccountResponse::class);
+		$mockResponse1->method('getEmail')->willReturn('user1@ionos.com');
+		$mockResponse1->method('getName')->willReturn('User One');
+
+		$mockResponse2 = $this->createMock(\IONOS\MailConfigurationAPI\Client\Model\MailAccountResponse::class);
+		$mockResponse2->method('getEmail')->willReturn('user2@ionos.com');
+		$mockResponse2->method('getName')->willReturn('User Two');
+
+		$this->logger->expects($this->exactly(2))
+			->method('debug');
+
+		$this->queryService->expects($this->once())
+			->method('getAllMailAccountResponses')
+			->willReturn([$mockResponse1, $mockResponse2]);
+
+		$result = $this->facade->getMailboxes();
+
+		$this->assertIsArray($result);
+		$this->assertCount(2, $result);
+		
+		$this->assertEquals('user1', $result[0]['userId']);
+		$this->assertEquals('user1@ionos.com', $result[0]['email']);
+		$this->assertEquals('User One', $result[0]['name']);
+		
+		$this->assertEquals('user2', $result[1]['userId']);
+		$this->assertEquals('user2@ionos.com', $result[1]['email']);
+		$this->assertEquals('User Two', $result[1]['name']);
+	}
+
+	public function testGetMailboxesHandlesException(): void {
+		$this->logger->expects($this->once())
+			->method('debug')
+			->with('Getting all IONOS mailboxes');
+
+		$this->queryService->expects($this->once())
+			->method('getAllMailAccountResponses')
+			->willThrowException(new \Exception('Service error'));
+
+		$this->logger->expects($this->once())
+			->method('error')
+			->with('Error getting IONOS mailboxes', $this->anything());
+
+		$result = $this->facade->getMailboxes();
+
+		$this->assertIsArray($result);
+		$this->assertEmpty($result);
+	}
+
+	public function testGetMailboxesHandlesEmailWithoutName(): void {
+		$mockResponse = $this->createMock(\IONOS\MailConfigurationAPI\Client\Model\MailAccountResponse::class);
+		$mockResponse->method('getEmail')->willReturn('user3@ionos.com');
+		$mockResponse->method('getName')->willReturn(null);
+
+		$this->logger->expects($this->exactly(2))
+			->method('debug');
+
+		$this->queryService->expects($this->once())
+			->method('getAllMailAccountResponses')
+			->willReturn([$mockResponse]);
+
+		$result = $this->facade->getMailboxes();
+
+		$this->assertIsArray($result);
+		$this->assertCount(1, $result);
+		$this->assertEquals('user3', $result[0]['userId']);
+		$this->assertEquals('user3@ionos.com', $result[0]['email']);
+		$this->assertEquals('user3', $result[0]['name']); // Falls back to userId
+	}
 }
diff --git a/tests/Unit/Provider/MailAccountProvider/Implementations/Ionos/Service/Core/IonosAccountQueryServiceTest.php b/tests/Unit/Provider/MailAccountProvider/Implementations/Ionos/Service/Core/IonosAccountQueryServiceTest.php
new file mode 100644
index 0000000000..b2b709bf82
--- /dev/null
+++ b/tests/Unit/Provider/MailAccountProvider/Implementations/Ionos/Service/Core/IonosAccountQueryServiceTest.php
@@ -0,0 +1,196 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2025 STRATO GmbH
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OCA\Mail\Tests\Unit\Provider\MailAccountProvider\Implementations\Ionos\Service\Core;
+
+use ChristophWurst\Nextcloud\Testing\TestCase;
+use IONOS\MailConfigurationAPI\Client\Api\MailConfigurationAPIApi;
+use IONOS\MailConfigurationAPI\Client\ApiException;
+use IONOS\MailConfigurationAPI\Client\Model\MailAccountResponse;
+use OCA\Mail\Provider\MailAccountProvider\Implementations\Ionos\Service\ApiMailConfigClientService;
+use OCA\Mail\Provider\MailAccountProvider\Implementations\Ionos\Service\Core\IonosAccountQueryService;
+use OCA\Mail\Provider\MailAccountProvider\Implementations\Ionos\Service\IonosConfigService;
+use OCP\IUser;
+use OCP\IUserSession;
+use PHPUnit\Framework\MockObject\MockObject;
+use Psr\Log\LoggerInterface;
+
+class IonosAccountQueryServiceTest extends TestCase {
+	private ApiMailConfigClientService&MockObject $apiClientService;
+	private IonosConfigService&MockObject $configService;
+	private IUserSession&MockObject $userSession;
+	private LoggerInterface&MockObject $logger;
+	private MailConfigurationAPIApi&MockObject $apiInstance;
+	private IonosAccountQueryService $service;
+
+	protected function setUp(): void {
+		parent::setUp();
+
+		$this->apiClientService = $this->createMock(ApiMailConfigClientService::class);
+		$this->configService = $this->createMock(IonosConfigService::class);
+		$this->userSession = $this->createMock(IUserSession::class);
+		$this->logger = $this->createMock(LoggerInterface::class);
+		$this->apiInstance = $this->createMock(MailConfigurationAPIApi::class);
+
+		$this->service = new IonosAccountQueryService(
+			$this->apiClientService,
+			$this->configService,
+			$this->userSession,
+			$this->logger,
+		);
+	}
+
+	public function testGetAllMailAccountResponsesReturnsEmptyArrayOnApiException(): void {
+		$externalRef = 'test-ref';
+
+		$this->configService->expects($this->once())
+			->method('getExternalReference')
+			->willReturn($externalRef);
+
+		$this->configService->expects($this->once())
+			->method('getBasicAuthUser')
+			->willReturn('user');
+
+		$this->configService->expects($this->once())
+			->method('getBasicAuthPassword')
+			->willReturn('pass');
+
+		$this->configService->expects($this->once())
+			->method('getAllowInsecure')
+			->willReturn(false);
+
+		$this->configService->expects($this->once())
+			->method('getApiBaseUrl')
+			->willReturn('https://api.example.com');
+
+		$this->apiClientService->expects($this->once())
+			->method('newClient')
+			->willReturn($this->createMock(\GuzzleHttp\ClientInterface::class));
+
+		$this->apiClientService->expects($this->once())
+			->method('newMailConfigurationAPIApi')
+			->willReturn($this->apiInstance);
+
+		$this->apiInstance->expects($this->once())
+			->method('getAllFunctionalAccounts')
+			->with('IONOS', $externalRef)
+			->willThrowException(new ApiException('API error', 500));
+
+		$this->logger->expects($this->atLeastOnce())
+			->method('debug');
+
+		$this->logger->expects($this->once())
+			->method('error')
+			->with('API error getting all IONOS mail accounts', $this->anything());
+
+		$result = $this->service->getAllMailAccountResponses();
+
+		$this->assertIsArray($result);
+		$this->assertEmpty($result);
+	}
+
+	public function testGetAllMailAccountResponsesReturnsAccountList(): void {
+		$externalRef = 'test-ref';
+		$mockResponse1 = $this->createMock(MailAccountResponse::class);
+		$mockResponse2 = $this->createMock(MailAccountResponse::class);
+		$responses = [$mockResponse1, $mockResponse2];
+
+		$this->configService->expects($this->once())
+			->method('getExternalReference')
+			->willReturn($externalRef);
+
+		$this->configService->expects($this->once())
+			->method('getBasicAuthUser')
+			->willReturn('user');
+
+		$this->configService->expects($this->once())
+			->method('getBasicAuthPassword')
+			->willReturn('pass');
+
+		$this->configService->expects($this->once())
+			->method('getAllowInsecure')
+			->willReturn(false);
+
+		$this->configService->expects($this->once())
+			->method('getApiBaseUrl')
+			->willReturn('https://api.example.com');
+
+		$this->apiClientService->expects($this->once())
+			->method('newClient')
+			->willReturn($this->createMock(\GuzzleHttp\ClientInterface::class));
+
+		$this->apiClientService->expects($this->once())
+			->method('newMailConfigurationAPIApi')
+			->willReturn($this->apiInstance);
+
+		$this->apiInstance->expects($this->once())
+			->method('getAllFunctionalAccounts')
+			->with('IONOS', $externalRef)
+			->willReturn($responses);
+
+		$this->logger->expects($this->atLeastOnce())
+			->method('debug');
+
+		$result = $this->service->getAllMailAccountResponses();
+
+		$this->assertIsArray($result);
+		$this->assertCount(2, $result);
+		$this->assertSame($mockResponse1, $result[0]);
+		$this->assertSame($mockResponse2, $result[1]);
+	}
+
+	public function testGetAllMailAccountResponsesHandlesException(): void {
+		$externalRef = 'test-ref';
+
+		$this->configService->expects($this->once())
+			->method('getExternalReference')
+			->willReturn($externalRef);
+
+		$this->configService->expects($this->once())
+			->method('getBasicAuthUser')
+			->willReturn('user');
+
+		$this->configService->expects($this->once())
+			->method('getBasicAuthPassword')
+			->willReturn('pass');
+
+		$this->configService->expects($this->once())
+			->method('getAllowInsecure')
+			->willReturn(false);
+
+		$this->configService->expects($this->once())
+			->method('getApiBaseUrl')
+			->willReturn('https://api.example.com');
+
+		$this->apiClientService->expects($this->once())
+			->method('newClient')
+			->willReturn($this->createMock(\GuzzleHttp\ClientInterface::class));
+
+		$this->apiClientService->expects($this->once())
+			->method('newMailConfigurationAPIApi')
+			->willReturn($this->apiInstance);
+
+		$this->apiInstance->expects($this->once())
+			->method('getAllFunctionalAccounts')
+			->with('IONOS', $externalRef)
+			->willThrowException(new \Exception('Unexpected error'));
+
+		$this->logger->expects($this->atLeastOnce())
+			->method('debug');
+
+		$this->logger->expects($this->once())
+			->method('error')
+			->with('Unexpected error getting all IONOS mail accounts', $this->anything());
+
+		$result = $this->service->getAllMailAccountResponses();
+
+		$this->assertIsArray($result);
+		$this->assertEmpty($result);
+	}
+}
diff --git a/tests/Unit/Provider/MailAccountProvider/Implementations/Ionos/Service/IonosMailServiceTest.php b/tests/Unit/Provider/MailAccountProvider/Implementations/Ionos/Service/IonosMailServiceTest.php
index 667010a520..a2c6f093a4 100644
--- a/tests/Unit/Provider/MailAccountProvider/Implementations/Ionos/Service/IonosMailServiceTest.php
+++ b/tests/Unit/Provider/MailAccountProvider/Implementations/Ionos/Service/IonosMailServiceTest.php
@@ -12,12 +12,12 @@
 use ChristophWurst\Nextcloud\Testing\TestCase;
 use GuzzleHttp\ClientInterface;
 use IONOS\MailConfigurationAPI\Client\Api\MailConfigurationAPIApi;
-use IONOS\MailConfigurationAPI\Client\Model\Imap;
+use IONOS\MailConfigurationAPI\Client\Model\ImapConfig;
 use IONOS\MailConfigurationAPI\Client\Model\MailAccountCreatedResponse;
 use IONOS\MailConfigurationAPI\Client\Model\MailAccountResponse;
 use IONOS\MailConfigurationAPI\Client\Model\MailAddonErrorMessage;
 use IONOS\MailConfigurationAPI\Client\Model\MailServer;
-use IONOS\MailConfigurationAPI\Client\Model\Smtp;
+use IONOS\MailConfigurationAPI\Client\Model\SmtpConfig;
 use OCA\Mail\Exception\ServiceException;
 use OCA\Mail\Provider\MailAccountProvider\Common\Dto\MailAccountConfig;
 use OCA\Mail\Provider\MailAccountProvider\Implementations\Ionos\Service\ApiMailConfigClientService;
@@ -121,8 +121,8 @@ private function createMockImapServer(
 		string $host = self::IMAP_HOST,
 		int $port = self::IMAP_PORT,
 		string $sslMode = 'ssl',
-	): Imap&MockObject {
-		$imapServer = $this->getMockBuilder(Imap::class)
+	): ImapConfig&MockObject {
+		$imapServer = $this->getMockBuilder(ImapConfig::class)
 			->disableOriginalConstructor()
 			->onlyMethods(['getHost', 'getPort', 'getSslMode'])
 			->getMock();
@@ -139,8 +139,8 @@ private function createMockSmtpServer(
 		string $host = self::SMTP_HOST,
 		int $port = self::SMTP_PORT,
 		string $sslMode = 'tls',
-	): Smtp&MockObject {
-		$smtpServer = $this->getMockBuilder(Smtp::class)
+	): SmtpConfig&MockObject {
+		$smtpServer = $this->getMockBuilder(SmtpConfig::class)
 			->disableOriginalConstructor()
 			->onlyMethods(['getHost', 'getPort', 'getSslMode'])
 			->getMock();
diff --git a/tests/Unit/Settings/ProviderAccountOverviewSettingsTest.php b/tests/Unit/Settings/ProviderAccountOverviewSettingsTest.php
new file mode 100644
index 0000000000..7f077bb855
--- /dev/null
+++ b/tests/Unit/Settings/ProviderAccountOverviewSettingsTest.php
@@ -0,0 +1,56 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2025 STRATO GmbH
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OCA\Mail\Tests\Unit\Settings;
+
+use ChristophWurst\Nextcloud\Testing\TestCase;
+use OCA\Mail\Settings\ProviderAccountOverviewSettings;
+use OCP\AppFramework\Http\TemplateResponse;
+
+class ProviderAccountOverviewSettingsTest extends TestCase {
+	private ProviderAccountOverviewSettings $settings;
+
+	protected function setUp(): void {
+		parent::setUp();
+		$this->settings = new ProviderAccountOverviewSettings();
+	}
+
+	public function testGetForm(): void {
+		$result = $this->settings->getForm();
+
+		$this->assertInstanceOf(TemplateResponse::class, $result);
+		$this->assertEquals('mail', $result->getAppName());
+		$this->assertEquals('settings-provider-account-overview', $result->getTemplateName());
+	}
+
+	public function testGetSection(): void {
+		$result = $this->settings->getSection();
+
+		$this->assertEquals('mail-provider-accounts', $result);
+	}
+
+	public function testGetPriority(): void {
+		$result = $this->settings->getPriority();
+
+		$this->assertEquals(50, $result);
+	}
+
+	public function testGetName(): void {
+		$result = $this->settings->getName();
+
+		$this->assertNull($result);
+	}
+
+	public function testGetAuthorizedAppConfig(): void {
+		$result = $this->settings->getAuthorizedAppConfig();
+
+		$this->assertIsArray($result);
+		$this->assertEmpty($result);
+	}
+}
diff --git a/tests/Unit/Settings/Section/MailProviderAccountsSectionTest.php b/tests/Unit/Settings/Section/MailProviderAccountsSectionTest.php
new file mode 100644
index 0000000000..b0ccaa6df8
--- /dev/null
+++ b/tests/Unit/Settings/Section/MailProviderAccountsSectionTest.php
@@ -0,0 +1,68 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2025 STRATO GmbH
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OCA\Mail\Tests\Unit\Settings\Section;
+
+use ChristophWurst\Nextcloud\Testing\TestCase;
+use OCA\Mail\Settings\Section\MailProviderAccountsSection;
+use OCP\IL10N;
+use OCP\IURLGenerator;
+use PHPUnit\Framework\MockObject\MockObject;
+
+class MailProviderAccountsSectionTest extends TestCase {
+	private IL10N&MockObject $l;
+	private IURLGenerator&MockObject $urlGenerator;
+	private MailProviderAccountsSection $section;
+
+	protected function setUp(): void {
+		parent::setUp();
+
+		$this->l = $this->createMock(IL10N::class);
+		$this->urlGenerator = $this->createMock(IURLGenerator::class);
+
+		$this->section = new MailProviderAccountsSection(
+			$this->l,
+			$this->urlGenerator,
+		);
+	}
+
+	public function testGetID(): void {
+		$result = $this->section->getID();
+
+		$this->assertEquals('mail-provider-accounts', $result);
+	}
+
+	public function testGetName(): void {
+		$this->l->expects($this->once())
+			->method('t')
+			->with('Email Provider Accounts')
+			->willReturn('Email Provider Accounts');
+
+		$result = $this->section->getName();
+
+		$this->assertEquals('Email Provider Accounts', $result);
+	}
+
+	public function testGetPriority(): void {
+		$result = $this->section->getPriority();
+
+		$this->assertEquals(55, $result);
+	}
+
+	public function testGetIcon(): void {
+		$this->urlGenerator->expects($this->once())
+			->method('imagePath')
+			->with('mail', 'mail.svg')
+			->willReturn('/apps/mail/img/mail.svg');
+
+		$result = $this->section->getIcon();
+
+		$this->assertEquals('/apps/mail/img/mail.svg', $result);
+	}
+}
diff --git a/webpack.common.js b/webpack.common.js
index b6db529241..b4fd9fcd32 100644
--- a/webpack.common.js
+++ b/webpack.common.js
@@ -53,6 +53,7 @@ module.exports = async () => ({
 		mail: path.join(__dirname, 'src/main.js'),
 		oauthpopup: path.join(__dirname, 'src/main-oauth-popup.js'),
 		settings: path.join(__dirname, 'src/main-settings'),
+		'provider-account-overview': path.join(__dirname, 'src/main-provider-account-overview'),
 		htmlresponse: path.join(__dirname, 'src/html-response.js'),
 	},
 	output: {