User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US; rv:1.9.0.15) Gecko/2009101601 Firefox/3.0.15 (.NET CLR 3.5.30729) Build Identifier: Thunderbird 3.0 RC 3 Continuously re-downloads the same messages via IMAP from Microsoft Exchange via IMAP rather than only downloading updates to the IMAP folders. Environment observed with: Server: Microsoft Exchange (via IMAP) 2003, 2007 and 14 Client OSs: Window Vista 64bit, CentOS 5.3 64bit Thunderbird versions: 3.0 (under CentOS 5.3), 3.0 RC3 (under Windows Vista 64bit) Reproducible: Always Steps to Reproduce: 1.Setup IMAP account on Microsoft Exchange 2003, 2007 or 14. 2.Populate inbox w/ 6300 messages (6300=current case, may not be relevant though) 3.Configure Thunderbird to connect to download messages, including the full body for indexing. Actual Results: Thunderbird downloads the messages in the inbox, and other folders, repeatedly. At some point it does appear to stop for a while, though reports are vague; from 2hrs to 1 day, the repeated downloading eventually stops. Expected Results: Messages are downloaded once, and only updates to inbox (or other folders) are downloaded. Example session: * OK The Microsoft Exchange IMAP4 service is ready. Welcome to E14 beta IMAP server. 1 capability * CAPABILITY IMAP4 IMAP4rev1 AUTH=GSSAPI AUTH=PLAIN STARTTLS IDLE NAMESPACE LITERAL+ 1 OK CAPABILITY completed. 2 authenticate plain + [login credentials] 2 OK AUTHENTICATE completed. 3 namespace * NAMESPACE (("" "/")) NIL NIL 3 OK NAMESPACE completed. 4 lsub "" "*" * LSUB () "/" Calendar * LSUB () "/" Contacts * LSUB () "/" Contacts1 * LSUB () "/" Drafts * LSUB () "/" "Deleted Items" * LSUB () "/" INBOX * LSUB () "/" Journal * LSUB () "/" "Junk E-mail" * LSUB () "/" Notes * LSUB () "/" "RSS Subscriptions" * LSUB () "/" Outbox * LSUB () "/" Sent * LSUB () "/" "Sent Items" * LSUB () "/" "Sync Issues" * LSUB () "/" Tasks * LSUB () "/" Trash * LSUB () "/" quarantine * LSUB () "/" INBOX/2007 * LSUB () "/" INBOX/2008 [cut] 4 OK LSUB completed. 5 list "" "INBOX" * LIST (\Marked \HasChildren) "/" INBOX 5 OK LIST completed. 6 select "INBOX" * 25899 EXISTS * 0 RECENT * FLAGS (\Seen \Answered \Flagged \Deleted \Draft $MDNSent) * OK [PERMANENTFLAGS (\Seen \Answered \Flagged \Deleted \Draft $MDNSent)] Permanent flags * OK [UNSEEN 7] Is the first unseen message * OK [UIDVALIDITY 962] UIDVALIDITY value * OK [UIDNEXT 1082414] The next unique identifier value 6 OK [READ-WRITE] SELECT completed. 7 UID fetch 1:* (FLAGS) * 1 FETCH (FLAGS (\Seen) UID 774804) * 2 FETCH (FLAGS (\Seen) UID 780676) * 3 FETCH (FLAGS (\Seen) UID 780677) * 4 FETCH (FLAGS (\Seen) UID 780678) * 5 FETCH (FLAGS (\Seen) UID 780679) * 6 FETCH (FLAGS (\Seen) UID 780680) * 7 FETCH (FLAGS () UID 780681) * 8 FETCH (FLAGS (\Seen) UID 780682) [cut]