Messages I've deleted in Thunderbird show up in RoundcubeThis is actually a Thunderbird issue: https://bugzilla.mozilla.org/show_bug.cgi?id=220064 If you'd like to see this issue addressed please vote for this ticket.UPDATE: As of Thunderbird 2.0 there is a hidden property named mail.imap.expunge_after_delete which will correct this issue if set to true. Please see the bug listed above for more details.