diff --git a/README.md b/README.md
index 955a64c..01b4321 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,8 @@
 docker-postfix
 ==============
 
+Modified from catatnight/postfix to add virtualhost support
+
 run postfix with smtp authentication (sasldb) in a docker container.
 TLS and OpenDKIM support are optional.
 
@@ -11,7 +13,7 @@ TLS and OpenDKIM support are optional.
 1. Build image
 
 	```bash
-	$ sudo docker pull catatnight/postfix
+	$ sudo docker pull benxo/postfix
 	```
 
 ## Usage
@@ -19,31 +21,47 @@ TLS and OpenDKIM support are optional.
 
 	```bash
 	$ sudo docker run -p 25:25 \
-			-e maildomain=mail.example.com -e smtp_user=user:pwd \
-			--name postfix -d catatnight/postfix
+			-e mailhostname=mail.example.com -e maildomain=example.com -e smtp_user=user:pwd \
+			--name postfix -d benxo/postfix
 	# Set multiple user credentials: -e smtp_user=user1:pwd1,user2:pwd2,...,userN:pwdN
 	```
 2. Enable OpenDKIM: save your domain key ```.private``` in ```/path/to/domainkeys```
 
 	```bash
 	$ sudo docker run -p 25:25 \
-			-e maildomain=mail.example.com -e smtp_user=user:pwd \
+			-e mailhostname=mail.example.com -e maildomain=example.com -e smtp_user=user:pwd \
 			-v /path/to/domainkeys:/etc/opendkim/domainkeys \
-			--name postfix -d catatnight/postfix
+			--name postfix -d benxo/postfix
 	```
 3. Enable TLS(587): save your SSL certificates ```.key``` and ```.crt``` to  ```/path/to/certs```
 
 	```bash
 	$ sudo docker run -p 587:587 \
-			-e maildomain=mail.example.com -e smtp_user=user:pwd \
+			-e mailhostname=mail.example.com -e maildomain=example.com -e smtp_user=user:pwd \
 			-v /path/to/certs:/etc/postfix/certs \
-			--name postfix -d catatnight/postfix
+			--name postfix -d benxo/postfix
 	```
 
+4. Full example (where you have symlinked certs from letsencrypt into /etc/postfix/certs):
+
+	``` bash
+    docker run -p 25:25 -p 587:587 \
+        -e mailhostname=mail.example.com -e maildomain=example.com -e smtp_user=user:pwd \
+        -e virtual_domains="mail.example.com test.example.com etc.example.com" \
+		-v /path/to/domainkeys:/etc/opendkim/domainkeys \
+        -v /etc/postfix/virtual:/etc/postfix/virtual \
+        -v /etc/letsencrypt/live:/etc/letsencrypt/live \
+        -v /etc/letsencrypt/archive:/etc/letsencrypt/archive \
+        -v /etc/postfix/certs:/etc/postfix/certs \
+        --name postfix -d benxo/postfix
+    ```
+
+
 ## Note
 + Login credential should be set to (`username@mail.example.com`, `password`) in Smtp Client
 + You can assign the port of MTA on the host machine to one other than 25 ([postfix how-to](http://www.postfix.org/MULTI_INSTANCE_README.html))
 + Read the reference below to find out how to generate domain keys and add public key to the domain's DNS records
++ If you want a persistent queue between restarts, you will need to extract an empty spool from /var/spool/postfix inside the container, preserving IDs and permissions! One is provided in postfix-spool.tgz
 
 ## Reference
 + [Postfix SASL Howto](http://www.postfix.org/SASL_README.html)
diff --git a/assets/install.sh b/assets/install.sh
index 0b2aaff..71d4370 100755
--- a/assets/install.sh
+++ b/assets/install.sh
@@ -26,18 +26,55 @@ service postfix start
 tail -f /var/log/mail.log
 EOF
 chmod +x /opt/postfix.sh
-postconf -e myhostname=$maildomain
+
+if [[ -z "$mailhostname" ]]; then
+  mailhostname=$maildomain
+fi
+
+postconf -e myhostname=$mailhostname
 postconf -F '*/*/chroot = n'
 
+# set up some email security as per https://ssl-tools.net/mailservers/ and 
+# https://serverfault.com/questions/670348/how-to-force-a-own-set-of-ciphers-in-postfix-2-11#670359 and
+# https://blog.tinned-software.net/harden-the-ssl-configuration-of-your-mailserver/
+
+postconf -e tls_ssl_options=NO_COMPRESSION
+
+postconf -e smtp_use_tls=yes
+postconf -e smtp_tls_security_level=may
+postconf -e "smtp_tls_protocols = !SSLv2, !SSLv3"
+postconf -e "smtp_tls_mandatory_protocols = !SSLv2, !SSLv3"
+postconf -e "smtp_tls_exclude_ciphers = DES-CBC3-SHA, EDH-RSA-DES-CBC3-SHA, RC2, RC4, aNULL"
+postconf -e smtp_tls_loglevel=1
+
+postconf -e smtpd_tls_security_level=may
+# postconf -e smtpd_tls_auth_only=yes
+postconf -e "smtpd_tls_protocols = !SSLv2, !SSLv3"
+postconf -e "smtpd_tls_mandatory_protocols = !SSLv2, !SSLv3"
+postconf -e smtpd_tls_ciphers=high
+postconf -e smtpd_tls_mandatory_ciphers=high
+postconf -e "smtpd_tls_exclude_ciphers = DES-CBC3-SHA, EDH-RSA-DES-CBC3-SHA, RC2, RC4, aNULL"
+postconf -e smtpd_tls_eecdh_grade=ultra
+
+# include 172.16/12 for docker
+postconf -e "mynetworks=127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128 172.16.0.0/12"
+
+
 ############
 # SASL SUPPORT FOR CLIENTS
 # The following options set parameters needed by Postfix to enable
 # Cyrus-SASL support for authentication of mail clients.
 ############
 # /etc/postfix/main.cf
-postconf -e smtpd_sasl_auth_enable=yes
+
+# this is enabled separately for smpt 25 and submission 587
+#postconf -e smtpd_sasl_auth_enable=yes
+
 postconf -e broken_sasl_auth_clients=yes
-postconf -e smtpd_recipient_restrictions=permit_sasl_authenticated,reject_unauth_destination
+postconf -e smtpd_sasl_security_options=noanonymous
+postconf -e "smtpd_recipient_restrictions=permit_mynetworks, permit_sasl_authenticated, reject_unauth_destination"
+postconf -e "smtpd_relay_restrictions = permit_mynetworks, permit_sasl_authenticated, reject_unauth_destination"
+
 # smtpd.conf
 cat >> /etc/postfix/sasl/smtpd.conf <<EOF
 pwcheck_method: auxprop
@@ -51,21 +88,47 @@ while IFS=':' read -r _user _pwd; do
 done < /tmp/passwd
 chown postfix.sasl /etc/sasldb2
 
+############
+# Virtual Domain support
+############
+if [[ "$virtual_domains" != "" ]]; then
+  postconf -e virtual_alias_maps=hash:/etc/postfix/virtual
+  postconf -e "virtual_alias_domains=$virtual_domains"
+  postmap /etc/postfix/virtual
+fi
+
 ############
 # Enable TLS
 ############
+
 if [[ -n "$(find /etc/postfix/certs -iname *.crt)" && -n "$(find /etc/postfix/certs -iname *.key)" ]]; then
+  SMTPD_TLS_CERT_FILE=$(find /etc/postfix/certs -iname *.crt)
+  SMTPD_TLS_KEY_FILE=$(find /etc/postfix/certs -iname *.key)
+fi
+
+# for letsencrypt
+if [[ -n "$(find /etc/postfix/certs -iname *.pem)" ]]; then
+  SMTPD_TLS_CERT_FILE=$(find /etc/postfix/certs -iname *full*.pem)
+  SMTPD_TLS_KEY_FILE=$(find /etc/postfix/certs -iname *priv*.pem)
+fi
+
+if [[ "$SMTPD_TLS_CERT_FILE" != "" ]]; then
   # /etc/postfix/main.cf
-  postconf -e smtpd_tls_cert_file=$(find /etc/postfix/certs -iname *.crt)
-  postconf -e smtpd_tls_key_file=$(find /etc/postfix/certs -iname *.key)
+  postconf -e smtpd_tls_cert_file=$SMTPD_TLS_CERT_FILE
+  postconf -e smtpd_tls_key_file=$SMTPD_TLS_KEY_FILE
   chmod 400 /etc/postfix/certs/*.*
   # /etc/postfix/master.cf
+  #postconf -M submission/inet="submission   inet   n   -   n   -   -   smtpd -v" # enable for debugging auth on 587
   postconf -M submission/inet="submission   inet   n   -   n   -   -   smtpd"
   postconf -P "submission/inet/syslog_name=postfix/submission"
-  postconf -P "submission/inet/smtpd_tls_security_level=encrypt"
+  postconf -P "submission/inet/smtpd_tls_security_level=encrypt" # comment out to test AUTH
   postconf -P "submission/inet/smtpd_sasl_auth_enable=yes"
   postconf -P "submission/inet/milter_macro_daemon_name=ORIGINATING"
   postconf -P "submission/inet/smtpd_recipient_restrictions=permit_sasl_authenticated,reject_unauth_destination"
+  postconf -P "submission/inet/tls_preempt_cipherlist=yes"
+
+  # only allow login from port 587
+  postconf -P "smtp/inet/smtpd_sasl_auth_enable=no"
 fi
 
 #############
@@ -117,14 +180,22 @@ cat >> /etc/opendkim/TrustedHosts <<EOF
 127.0.0.1
 localhost
 192.168.0.1/24
+172.16.0.0/12
 
 *.$maildomain
 EOF
-cat >> /etc/opendkim/KeyTable <<EOF
-mail._domainkey.$maildomain $maildomain:mail:$(find /etc/opendkim/domainkeys -iname *.private)
-EOF
-cat >> /etc/opendkim/SigningTable <<EOF
-*@$maildomain mail._domainkey.$maildomain
-EOF
+
+for d in $virtual_domains; do
+  echo >> /etc/opendkim/TrustedHosts "*.$d"
+done
+
+for d in $maildomain $virtual_domains; do
+  private_key_file=$(find /etc/opendkim/domainkeys/$d -iname *.private)
+  if [[ "$private_key_file" != "" ]]; then
+    echo >> /etc/opendkim/KeyTable     "mail._domainkey.$d $d:mail:$private_key_file"
+    echo >> /etc/opendkim/SigningTable "*@$d mail._domainkey.$d"
+  fi
+done
+
 chown opendkim:opendkim $(find /etc/opendkim/domainkeys -iname *.private)
-chmod 400 $(find /etc/opendkim/domainkeys -iname *.private)
\ No newline at end of file
+chmod 400 $(find /etc/opendkim/domainkeys -iname *.private)
diff --git a/build.sh b/build.sh
index d7b5420..ec5cca9 100755
--- a/build.sh
+++ b/build.sh
@@ -1,3 +1,3 @@
-#!/bin/bash
+#!/bin/bash -xe
 
-docker build -t catatnight/postfix .
\ No newline at end of file
+docker build -t benxo/postfix .
diff --git a/postfix-spool.tgz b/postfix-spool.tgz
new file mode 100644
index 0000000..fd95d0b
Binary files /dev/null and b/postfix-spool.tgz differ