Problem with sieve not triggering randomly?

[Stephan Bosch]

On 5/15/2015 4:58 PM, Chris Adams wrote:
> I'm running CentOS 7.1 with Dovecot 2.2.10 (CentOS packaged version).  I
> have Postfix feeding messages to Dovecot for local delivery via LMTP,
> and I have Amavisd for spam filtering.  For messages above a certain
> threshold, Amavisd adds the "X-Spam-Flag: YES" header, and I file that
> into the Spam folder using a default (system-wide) sieve script (there
> aren't any per-user sieve scripts set up):
>
> require "fileinto";
> if header :contains "X-Spam-Flag" "YES" {
> 	fileinto "Spam";
> }
>
> I can see it work on my test messages and from lmtp log entries.
>
> However, it doesn't seem to always work.  I had a user complain about a
> spam increase, and I looked in their mailbox.  I see a message with the
> "X-Spam-Flag: YES" header, but it is in the INBOX (and the corresponding
> lmtp log entry shows that's where it went).
>
> Why would the sieve script work on some messages and not others?  I
> don't see any errors in the log.  I see a bunch of messages from the
> same source to different users, and they were all filed into INBOX, not
> Spam.
>
> Looking at the message in question, it is a pretty bogus message.  There
> are multiple From: and Subject: headers.  Would that cause sieve to
> "punt" on the message (but not log anything about it)?

You can check the handling of a particular message yourself using the
sieve-test tool (there is a man page for it). By specifying the `-t -
-Tlevel=matching` options, you'll get detailed information on why a
particular decision is made.

Without insight in your configuration (output from `dovecot -n`) and an
example of a message that is mishandled, I cannot tell you more.

Regards,

Stephan.