Dean Manners, on 1/14/2008 3:39 AM, said the following:
-Postfix 2.3.4 with MySQL backend -Dovecot 1.0.rc26 with MySQL backend, using only deliver.
Both of these are old, but the dovecot is very possibly the problem - if memory serves, that version was buggy.
You really need to update to a current release version (1.0.11 is current), whether it fixes this particular problem or not.
I also strongly recommend updating postfix... 2.3.4 is over a year - and more importantly 9 patch levels AND a full release+6 patch levels - old, with another major release (2.5) imminent.
Lots of good reasons to upgrade postfix, but normal caveats apply - ie, read the release notes to see if anything changed that will require you to modify current config files.
--
Best regards,
Charles