Hello. 
I think a search box on every filter rule window would be very useful. It would
help in tracking down any filter that may have been created incorrectly or that
needs to be edited or deleted. This would also save time instead of having to
scroll through potentially dozens of entries in the filter. 
Perhaps once a search has been done the screen jumps to the specific filter and
highlights it, like in Firefox when using Ctrl + F to find something on the
page.

Thank you.

I have created a prototype that gives 3 types of search:
  Target Folder
  Search Condition
  Add Tag

the search type is selected via a "Change search properties..." button on the
left of the "Search filters" box. Once you select a behavior you can search for
that value

e.g. 
  Where Filter Action is Move to Folder "xxxx"
  Select "Target Folder" and enter xxxx

  Where Subject contains "yyyy"
  Select Search Condition and enter yyyy

  Where Sender is "fred"
  Select Search Condition and enter fred

  Where Action is Add Tag  "personal"
  Select "Add Tag" and enter personal

Created an attachment (id=7874) [details]
qF 2.6 prerelease 95

Protoype with Search Types selector button. This should probably cover 95% of
the required cases.

Created an attachment (id=7877) [details]
Duplicates Found

Created an attachment (id=7878) [details]
Listed Result

(In reply to comment #3)
> Created an attachment (id=7877) [details] [details]
> Duplicates Found
> 


Using quickFilters 2.6pre95 I created added a fake email address
"noreply@test.com" to 3 different folders. 
Search function works great and finds all 3 fake addresses and shows the
correct 3 folders. 
Right clicking and selecting "Remove Duplicate Condition" does scroll to the
correct entry, but it does not highlight the entry in red.

Created an attachment (id=7879) [details]
qF 2.6 prerelease 105

I just made a fix in the loop going through the visible list which should make
it more reliable when the matched duplicate is scrolled off screen. It should
scroll and highlight. If not please enable debug mode and post the log from
console2.

Created an attachment (id=7882) [details]
qF 2.6 prerelease 140

Add l10n and support for searching for "Reply with Template". This search is
partial and case insensitive and based on the Subject of the template.

Using qF 2.6 pre140 I still cannot get duplicates to highlight in red. All
duplicates are found correctly and when there is a large filter list it scrolls
properly after seeming to "hang" for a few seconds; during this time the window
is blank. 

When pressing the Find duplicate attributes button should it automatically
populate the drop down box or will users continue to have to then click the
drop down arrow manually? It seems that it would be more convenient to have it
listed automatically. 

(In reply to comment #8)
> Using qF 2.6 pre140 I still cannot get duplicates to highlight in red. All
> duplicates are found correctly and when there is a large filter list it scrolls
> properly after seeming to "hang" for a few seconds; during this time the window
> is blank. 
Ok, maybe I should add a throbber or other animation to show activity - maybe
in the next version. I haven't actually worked on the background color this
much, but that should be relatively easy to fix - are you using a full theme or
the standard one? What OS?


> 
> When pressing the Find duplicate attributes button should it automatically
> populate the drop down box or will users continue to have to then click the
> drop down arrow manually? It seems that it would be more convenient to have it
> listed automatically. 

Not sure, I would usually expect more than one result but one might argue
selecting the top item in the list could be convenient. You will still have to
re-run the duplicates after editing the filter as it currently doesn't signal
"back" to the list that something might have changed. So I think it is not such
a big deal. A label "please select a duplicate" would be good though.

Note: the implementation works for Thunderbird. SeaMonkey and Postbox do not
have the Search Box, but it would be desirable to add one to these mail clients
as well. I suggest we file a separate bug for each application as it is a
non-trivial request (the Filter List in Sm + Pb is implemented differently from
Thunderbird).