Thunderbird Hangs: Create Filter -> Create New Filter

[WoofGrrrr]

Thunderbird 147.0.1 64-bit (up to date) on Windows 11 Pro 25H5 (up to date)
QuickFilters 6.1 (2026-01-29) (I bought the Pro license so I could create custom templates.)

I updated to 147.0.1 as soon as it was available.
I have Extensions set to auto-update.
I do NOT have the QuickFilters Button on my Toolbar.

I did this:
1.Moved a message into a folder
2. Right-Clicked on the message in the folder
3. Selected "Create New Folder" -> The Create Filters window opened
4. Selected my custom filter template named "From Sender's Domain or Sub-Domain"
5. Clicked the "Create New Filter" button near the lower-right of the window

The window just hangs. The cursor is a big, green hourglass
I moved my cursor over to the main window and I see the same thing. Thunderbird is hung up with the same green hourglass.
I had to kill the app and start it again.

Setup:

• Add parent folder names: checked
• Delimiter: / (just a forward slash)
• Maximum folder levels: 3

Everything was working the last time I did this. Perhaps a week ago???

Here is the info for the filter Template:

• Manually Run: checked
• Getting New Mail: checked
• "Filter before Spam Classification" is selected
• Match any of the following: selected
• Match: From ends with @%from(domain.root)%.%from(domain.extension)%
• Match: From ends with .%from(domain.root)%.%from(domain.extension)%
• Action: Stop Filter Execution

I will remove the extension, download it from here (GitHub) and install that to see if that fixes the problem.

[WoofGrrrr]

I removed the extension, restarted Thunderbird, re-installed it from the XPI file, and tried again. Same result.

I killed and restarted the app, but this time I chose a different, built-in template. It worked.

Perhaps a problem with the variable substitutions???

[RealRaven2000]

Can you export the custom filter template from local folders? Select it, then click backup on the toolbar while holding down CTRL. You can attach the generated json file here. Is it triggered by any email?

[WoofGrrrr]

Here is the result WITH the CTRL key is held down.

Local Folders_2026-02-09_14-42.json

And WITHOUT the CTRL key held down:

Local Folders_2026-02-09_14-38.json

I have used this template many, many times in the past. It has worked really well. In fact, I initially bought the PRO license JUST so I could create and use this template. I rarely use any other one. It's the best way I know of to catch all emails and only emails from a given domain: From Ends with "@domain.com" OR From Ends with ".domain.com"

Now if only I could use more-advanced logic with both OR and AND the way that BetterBird allows. I'd like to AND this OR with a subject match: (From Ends with "@domain.com" OR From Ends with ".domain.com") AND Subject Contains "xxyyzz"

I find your QuickFilters Extension absolutely essential now. I am glad to have paid for it.

In other words, THANK YOU!

[RealRaven2000]

ok, I imported your template into the latest Thunderbird beta 148.0b4 - worked for me, here is what it generated, I used context menu >> Create Filter from Message... :

btw why do you add "Stop filter execution" - won't moving the message take care of that? what version of Thunderbird (Betterbird) are you running. Maybe the rules fails because you merge into an existing filter? Or there is a special email that triggers this...

you can use the template in Betterbird as well - there is only a caveat that merging new rules into existing filters may fail if you mix any / all - it is kind of difficult to determine where to add the new rules in an already existing filter in that case. I am trying my best.

[RealRaven2000]

You might also want to try simplifying the rules to this - I think this should do the same?

@%from(domain)%
.%from(domain)%

[WoofGrrrr]

Unfortunately, that doesn't get me what I want.

For example, if I want to create a filter for an email from "xxx@shared1.ccsend.com", those rules would get me this:

• @shared1.ccsend.com
• .shared1.ccsend.com

But what I want is:

• @ccsend.com
• .ccsend.com

And why do I include "Stop filter execution"? That's just me. I want it to be explicitly stated. And, frankly, I hadn't considered that "Move to" was an implicit stop! I guess that Thunderbird changes the ordering of the Actions so that it will be applied last.

And perhaps I was hoping to find a way for my userChrome.css or userContent.css to change how a rule looks if there were an explicit stop in the rule. No such luck. There's no information in the HTML in the Rules List that would let me do that. I would be happy just to change the text color. Red, maybe.

If you look at the file I created without the CTRL key pressed, it looks like there's some junk.

I'm going to try cleaning that up, maybe delete my templates, and try again.

[WoofGrrrr]

Didn't mean to close this. Don't have the permission to re-open.

[WoofGrrrr]

BTW - When I create a new template, I get Message Filters window that includes not only mu templates but all then "junk" I mentioned:

[WoofGrrrr]

Oh, yes, I forgot to say this.

I don't actually use BetterBird day-to-day, but I do run it from time to time to make sure that the extensions I'm working on still work there.

The one thing that intrigues me about it, as I'm sure you figured, is the advanced logic in the matching rules.

Without those I find myself having to create multiple rules to do the same thing in Thunderbird.

[WoofGrrrr]

I deleted my templates, including all the "junk", and created my template again, and now it works. No problem.

[WoofGrrrr]

BTW.... I believe that I created that "junk" when I first got my Pro License so I could create my own templates. I got confused about the prefix "quickFilterCustomTemplate:" in the filter names on that page for which I sent the screenshot.

I didn't name my template that way, so I thought I had done something wrong, so I edited the rule to delete the prefix.

I just HATE admitting to being an idiot!!! ;-)

[RealRaven2000]

BTW - When I create a new template, I get Message Filters window that includes not only mu templates but all then "junk" I mentioned:

the official way to just edit your custom templates, is to go through quickFilters settings >> Advanced >> Custom Templates [Edit...]

With quickFilters I am storing everything filter related as filters, which also includes templates. (Actually I do not store them at all I trick Thunderbird by lying to it and saying these are filters too - and I am just hacking the filter editor to give you the additional custom variables selection)

Because I am using the built in filters serer, architecture / Editor / filter list for everything. I do inject the toolbar into the Thunderbird message filters dialog and add the search box. When you go the way I described above I simply add "quickFilterCustomTemplate" to the search box:

[WoofGrrrr]

Yeah, I figured things out... finally. And thanks for making sure of that.

I do understand what you're doing is complicated and the way you are forced to do it is weird. If only there were a Web Extension API for MessageFilters, no? I'm still waiting for an API for Virtual Folders (Saved Searches, they call them now.) It will be a long, long wait (i.e. never.) The built-in Saved Searches are broken.

I just want you to know that I DO really appreciate having quickFilters. It's great work. It saves me a lot of time.

Were you able to check whether it was those "junk" templates that caused Thunderbird to completely hang?