[Dovecot] Improving interaction/performance with Mail.app

Sean Kamath kamath at geekoids.com
Wed Aug 2 02:44:49 EEST 2006

On July 1, Alan Schmitt wrote:
>>>> What OS are you using in server side? And what filesystem?
>>> Mac OS X.4.7, with HFS+ as files system.
>> I think I've heard before that Dovecot doesn't behave too great with
>> OSX..
>This might be the cause. I've had the plan to move my IMAP server to  
>a linux box, this might be the good time.
>> Hmm. I guess it's time to put this in wiki:
>> http://wiki.dovecot.org/Debugging/ProcessTracing
>Good to know. I just need to find a way to reproduce the problem.
>Thanks a lot for your help,

I just moved to Dovecot.  I'm looking forward to figuring out how to
allow users to have access to (old) email in mbox format, an have all
new mailboxes go to maildirs. . . But I digress.

When we switched, no one complained of performance issues -- except

mail.app would seem to stall on caching a message, then report that it
was reconnecting, and move a bit further, then stall. . .

What apparently was happening was the dovecot was polling for
/dev/urandom, over and over again, waiting for some random bits, and
Mail.app would timeout and reconnect.  Turning off SSL made it MUCH

Of course, that's not a solution.

So, I hunted the mailing lists, and ran across some notes about dovecot
using /dev/urandom a little too enthusiastically.  I haven't had a
chance to grub through the code (hard to do with a 2-year old that
won't sleep until midnight on many a nights!), and this post is
somewhat premature, but I'm curious if turning off SSL removes the

Of course, switching to a Linux server will (sort of) negate the problem,
in that apparently Linux is a little faster at finding random bits (I
guess, I've never looked into it).

My server is Solaris 9.  My client is Mail.app from 10.3.9.

As I grub through the code, I'll try and identify cryptographically
significant randomness from non-cryptographically significant randomness.


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