On Mon, 18 Jul 2005, Marc Blank wrote:
I've noticed that on at least one server running UW-IMAP, that an empty folder (in this case Drafts), when SELECTed at various times and in various sessions, keeps returning a different UIDVALIDITY value. Is this correct behavior?
It's permitted behavior by the IMAP specification. UW imapd does not consider it to be good behavior, but it's unavoidable.
What's going on is that the file is truly empty, and thus does not have any metadata. In traditional UNIX mailbox format, the widely-derided "DO NOT DELETE" internal pseudo-message (which UW imapd, Pine, etc. hides) contains the metadata; but this upsets some people, and so they do things to prevent the pseudo-message and/or destroy it. [The issue is shell tests that treat empty files as "no mail" and non-empty files as "mail exists"]
Fortunately, since the mailbox is empty, a changing UIDVALIDITY value should not overly-upset a client. The client should just say "oh well" and update its record of the UIDVALIDITY. Since, as you saw, this can be routine in some environments, it's not an event that is worth logging, much less complainig to the user.
In some formats, such as UW imapd's preferred mbx, an empty mailbox is not an empty file, and thus this problem does not occur.
-- Mark -- http://staff.washington.edu/mrc Science does not emerge from voting, party politics, or public debate. Si vis pacem, para bellum. _______________________________________________ Imap-uw mailing list Imap-uw@u.washington.edu https://mailman1.u.washington.edu/mailman/listinfo/imap-uw
