I went back and checked this again after over a year. Actually, the change I made to thunderbird didn't really affect the UIDs assigned by zimbra that occur when imap appending a fairly long list of messages. For unknown reasons, zimbra just randomly skips over a UID value and leaves gaps of one UID value in the increasing sequence. Technically this doesn't violate the base imap spec rfc3501 but it causes problems with qresync extension in that all the gaps are reported as vanished messages which they are not.
Also, since zimbra assigns UIDs from an account global counter, this also produces even larger gaps when messages are copied to different folders. These large gaps are also reported as vanished with qresync enabled. This wouldn't be a problem if zimbra used a separate UID assignment counter for each mailbox/folder like other qresync compliant servers or if zimbra just didn't report the gaps it creates as vanished UIDs.
Also, since zimbra assigns UIDs from an account global counter, this also produces even larger gaps when messages are copied to different folders. These large gaps are also reported as vanished with qresync enabled. This wouldn't be a problem if zimbra used a separate UID assignment counter for each mailbox/folder like other qresync compliant servers or if zimbra just didn't report the gaps it creates as vanished UIDs.
Statistics: Posted by gds — Sun Jun 18, 2023 6:19 pm