Tue, 18 Jan 2005

Slow POP connections

— SjG @ 12:29 pm

OK, this is an esoteric one, but I’m happy to report there is a simple solution.

We migrated Stacy over to using Thunderbird (from Outlook Express) on her Mac to cut down on the spam. In the process, we upgraded her to OS X.
Strangely, while POP connections to our local QMail server are nearly instantaneous on the Windows machines, there would be a 30-40 second delay for her. It wasn’t a Thunderbird problem — we could replicate the problem by telnetting to port 110 — and only from the Mac OS X machines.

Karl finally succeeded in diagnosing the problem. QMail uses tcpserver to wrap connections. tcpserver, in turn, checks back via ident. The Mac OS machines don’t have identd running by default. By running tcpserver with the “-R” option (disabling the ident lookup), everything works brilliantly as it should.

2 responses to “Slow POP connections”

  1. Daniel Haslinger says:

    You’re brilliant !!
    Due to slow POP connections but extreme performant SMTP connections I searched Google for “qmail pop slow” and got to your site!
    We found out that on the POP tcpserver entry had no -R option, now ev’rything works correctly..

  2. T says:

    Thankyou for providing that well needed moment of clarity.
    After reading your post I was sure I had stumbled across this problem some time in the past, and remembered the solution is indeed simple. For anyone else who might wonder, on our Gentoo system, this option was hiding in /var/qmail/control/conf-common as TCPSERVER_OPTS. Maybe I can use this page as a reminder next time I need it 😉

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