Rated 4 out of 5 stars

I'm thankful to have found FiltaQuilla and given the complexity of regular expressions I was girding myself for some heavy brain twisting to achieve the filter that I needed (more on that later). Here is a GREAT tool for testing regular expressions https://regex101.com/#pcre

After installation it is is a pretty invisible add-on. Like some others have posted after installation, I restarted TB and went to edit an existing filter. No sign of any additional filter logic :-(. So I checked the options - only one Filter action and one Search Term (Subject Regex match) was enabled. Don't understand why so few search terms are enabled by I went ahead and enabled 'Header Regex match' which is what I needed and restarted TB as instructed.

Went back to edit my existing filter and the dropdown search terms didn't have ANY new options. :-( Hmmm

Started to create a new filter and presto - the new search terms were in the drop down. So I suspect that THIS is the mystery that leads many to believe that the addon doesn't work. Existing filters don't offer any of the new search terms - period. You have to create a new filter and then you will see the new FiltaQuilla search terms offered.

Next has to do with what frankly most of us probably want FiltaQuilla for - more sophisticated filtering of headers. Here is where I think FiltaQuilla can be improved on. The Header Match regex search term is unnecessarily cryptic and the documentation really could be much better. It doesn't work the way you would expect. You can't search individual headers, you are limited to the available properties that are set on the nsIMsgDBHdr object associated with the message. You would think that one might be the 'From' header but, no, you need to use 'sender' as the value. This strikes me as an area that could be much more simplified and possibly expanded on so that any header record can be searched.

One cool bonus that I stumbled on. You have access to FiltaQuilla's search terms when you create a permanent search folder. To get to them, right-click the folder you want to setup a search for, select 'Search Messages...' On the Search pop-up (leave it blank), go to the bottom and click 'Save as Search folder'. Another window will pop and you can construct your search in that window using all of FiltaQuilla's search terms just as you would when you create a filter.

Overall however, I am giving FiltaQuilla 4 stars because without it I would not be able to do the filtering that I need to do and I do appreciate that someone put time and effort into providing this functionality for free.

Finally here is my contribution. If you want to rid yourself of all of the spam coming from all of the new top level domains (TLD) here is a regex that will do the job without butchering your folder.

sender:/.*@.*\.com>?\s*(\(.+\))?$/im

Just setup a filter, click 'Match all of the following' and for each filter step, select 'Header Regex Match' then doesn't match and then sender:/.*@.*\.com>?\s*(\(.+\))?$/im

Add as many fiter steps as need to include only the top level domains that you want to have in your inbox. Set the filter action to move the matched entries (TLDs that you DO NOT want) into a Junk folder or whatever you want to do.

The above regex will not allow senders from the many of the new creatively done domains such as spam.com-something.weird to leak through.

Enjoy!

This review is for a previous version of the add-on (1.3.1).