Tom Sommer wrote: > Sometimes when I browse messages in my folders, or move messages from > one folder to another - I get this error in Thunderbird: > http://pub.tsn.dk/screendumps/dovecot.bug.1.jpg It's a thunderbird bug: https://bugzilla.mozilla.org/show_bug.cgi?id=263904 Dovecot has a client workaround in 1.0-test51 and later versions.