Comment 5 for bug 119899

I also have this issue - I have tried filtering on List-ID to separate mails
based on which mailing list they were sent to.
A view filter utilising this matches no entries, even though there are MANY
(most?) mails in the folder containing the header header
List-ID: <email address hidden>

I had already voted on this issue, but didn't want to spam. I've just retested
with the latest nightly trunk build (2003071704 on Windows 2000), with no change
in behaviour.

I am quite willing to enable debugging (NSPR logging), though a brief look
through the source suggested that there were no useful log points for this problem.

The mail source is IMAP, if that makes a difference...

Considering comment 2, I tested with mail filters (which I don't usually use),
and an attempt to label mails according to the same criteria. This appeared to
succeed (according to the filter logging), but no mails were actually labelled.
I restarted mozilla, and all my view customisations had disappeared. Attempts to
add any new views failed with

Error: uncaught exception: [Exception... "Component returned failure code:
0x80004005 (NS_ERROR_FAILURE) [nsIMsgMailViewList.addMailView]" nsresult:
"0x80004005 (NS_ERROR_FAILURE)" location: "JS frame ::
chrome://messenger/content/mailViewSetup.js :: onOK :: line 89" data: no]

Sorry if I'm mixing up problems here, but I'm adding these items in case they
are relevant.