Mac Forum / Applications / Eudora / October 2006

My issues are design flaws, not coding bugs.

1. A filter that moves a message between folders ends filtering of that
message absolutely. This applies to all types of mail, not just IMAP.

2. SpamWatch filtering of mail in IMAP mailboxes is dependent on an IMAP
extension that is relatively rare. There is a workaround documented in
the Qualcomm online support KB that mostly works, but it leaves the
"Junk" menu item essentially broken. There's no logical reason for that,
just a lack of of attention to the IMAP functionality of the program.

3. Moving a message into an IMAP mailbox (via filtering or manually)
switches the personality to that of the IMAP account, even if it has
already been set to some other personality by filtering. An example of
where this causes trouble is in using tagged addresses [0] for
discussion lists. With POP (i.e. client-side message storage) you can
have a filter set a personality and then move the message to a mailbox
just for that list. Replies will use the address of the personality set
before the mailbox move. IMAP cannot be made to work that way, because
moving into an IMAP mailbox sets the personality, but because of problem
#1 you can't have a filter repair the damage.

4. There is no way to filter on the real Date header content because
what you get in the Date 'header' for filtering is actually the result
of whatever the Date Display settings generates. There is also no way to  
on a logical date like "more than 2 days old" or "more than a day in the
future." That would be in the class of a feature request, but it would
replace any need to filter on the real Date header.

[0] A common MTA feature where any 'username+tag' or 'username-tag'
address will deliver to the 'username' mailbox.