On Tue, 2 Apr 2002, Alex Esselstein wrote: > I was wondering if any administrators (with some Outlook 2000 and above > users) experience the issue of UW-IMAP closing the connection. I read from a > different list serve that it had to do with IMAP NOOP commands triggering a > 1/2 minute timeout...
You've heard a highly-distorted account. It has nothing to do with NOOP commands, nor is there any 1/2 minute timeout. There are several issues, all of which are directly traceable to Outlook not doing the right thing. Issue (1): Certain IMAP clients, including Outlook, have a tendency to open multiple IMAP sessions simultaneously to the same mailbox unless it is carefully configured (and used!) to avoid this. The traditional UNIX mailbox format is not ameniable to multiple read-write sessions being open simultaneously, and each open of a mailbox in this format kills any previous session that is open on that mailbox. Issue (2): Certain IMAP clients, including Outlook, have a tendency to close the IMAP session without first issuing a proper LOGOUT command. This causes a "Command stream end of file" in the logs from the IMAP server, which misleads people into believing that there is some server-based problem. Issue (3): Outlook and Outlook Express use the IMAP IDLE extension to go into a mode in which the client is alerted to new messages automatically without having to transmit a periodic NOOP to cycle the protocol (effectively polling the server). This isn't surprising; Microsoft instigated the development of that extension. Unfortunately, Outlook and Outlook Express violate a part of the IDLE specification which requires that the client end the IDLE within 29 minutes (and, if appropriate, issue a new IDLE), in order to renew the session and avoid the IMAP inactivity autologout which occurs at 30 minutes of no activity from the client. Since Outlook and Outlook Express do not do anything to renew the session, it dies at the 30 minute autologout as per the specification. As noted above, clients that do not use IDLE typically send a NOOP every few minutes, which keeps the session active and avoids the autologout. So why not just disable IDLE in the server? Unfortunately, disabling server support for the IDLE extension does not cause Outlook and Outlook Express to revert to the NOOP behavior; they just don't send anything at all. Microsoft acknowledged the problem in Outlook Express, but since Outlook Express is effectively a dead product it is unlikely that it will ever be fixed. I don't know what the plans are to deal with this in Outlook. To summarize: The problems are entirely at the Outlook end. The best way to get them resolved is to file problem reports with Microsoft. -- Mark -- http://staff.washington.edu/mrc Science does not emerge from voting, party politics, or public debate. "A single glass of champagne imparts a feeling of exhiliaration. The nerves are braced; the imagination is agreeably strirred; the wits become more nimble. A bottle produces a contrary effect. Excess causes a comatose insensibility. So it is with war; and the quality of both is best discovered by sipping." -- Winston Churchill
