I think there is a important convenience function missing to speed up the use of filters/rules.
Currently, if you want to set up a rule/filter you need to remember or copy all details you want to react on before starting to create the rule, then you need to 1) click on the email-homepage, 2) filter 3) new 4) type in a name 5) type an email/ subject 6) What to do if true 7) save
it works and it does what is should.
However what I love in MS office is that this can be done in 3 clicks. The function accessible strait on the top and already pre-populated if you go this direct way.
What could be added to Thunderbird:
if with a right click in an email, an "add filter" option would appear (for example under Organisation) and this brings you straight to the "new filter" window with 3 fields filled out:
1) name of the filter contains: the subject of the email
2)subject - contains: subject of the email
3)from - contains: sender of the email
Then you only need to change/delete a condition and 90% of the requirements are met.
It may sounds very silly, but I have to say this functionality in MS saved me so much time, with all "update" or "notice" email just been sorted away, maybe deleted or whatever.
I hope this can be considered and implemented and makes Thunderbird a little bit better.
Daniel