Storing message flags for a message which was just deleted results in a logged error.
If the same header field is requested multiple times, it should only be returned once. (imaptest)
Message-Id and In-Reply-To fields should be encoded if they contain "
IMAP SORT should use character set (imaptest)
Server should send NO [TRYCREATE] response if trying to append to nonexisting mailbox. (RFC 3501)
Do not send EXPUNGE in reply to FETCH/STORE/SEARCH/SORT.