[sylpheed:35515] Problems with filters on IMAP accounts

[Stefan A.]

Hi guys, I recently started using Sylpheed and I am very satisfied
with its speed and stability so far. Keep up the great work! To make
the transition to Sylpheed complete, however, I need reliable
filtering of IMAP messages, which I haven't been able to get working
yet, and I was hoping you may be able to help.

I have a filter rule "sylph-clamassassin" which is set up as follows:
If all of the following conditions match:
  Result of command: ~/sylph-clamassassin-wrapper.sh
Perform the following actions:
  Move to folder: #mh/Mailbox/inbox/THREAT_DETECTED

The bash script scans messages and returns "true" if a threat is
found. It works fine when run manually on local folders (i.e. when
running Tools -> Filter messages), but I haven't been able to get it
to scan email messages automatically on IMAP folders yet. The relevant
options ("Filter new messages in INBOX on receiving" in Account
Preferences -> Receive) are all set, but messages sometimes get
filtered, sometimes not. When I fetch emails manually by clicking
"Get", for example, filtering usually works, but when Sylpheed fetches
emails on its own, it usually doesn't. Actions are also sometimes not
executed as defined. I tried setting marks and colours for identified
messages, but Sylpheed would only set a mark and not the colour when
running the filter on IMAP folders, whereas both are set correctly on
local folders. I can't quite point my finger to what is causing the
problem, so I was hoping you guys may be able to give advice. Any
thoughts?

sylph-clamassassin-wrapper.sh: http://pastebin.com/EP00MnXc
Sylpheed: version 3.2.0 beta 5
OS: Ubuntu 12.04 LTS (Precise Pangolin), Linux 3.2.0-35, x86_64