[pkg-fetchmail-maint] Bug#398700: Fetchmail only saves first 9 e-mails.for first 30 minutes

[Patrick Horn]

Package: fetchmail
Version: 6.3.4-7

Whenever I start fetchmail each day, I usually have received at least 20-40 e-mails on the POP server.

Fetchmail immediately gets the first 9 e-mails and puts them in the IMAP folder, and then sits with the rest.
Unfortunately, restarting fetchmail does not help. It is as if I never had more than 9 e-mails.

If any e-mails are sent after fetchmail starts, it will download those immediately, but it doesn't see the rest from the original batch.

Exactly 30 minutes later, fetchmail suddenly finds the rest of the e-mails (even if there are over 30 of them), and saves them all.

The 9 e-mail limit only seems reproducible once a day.

The strange thing is that the log indicates that it downloaded all of the e-mails to begin with, while only 9 showed up in the IMAP folder:
Nov 14 18:19:46 patrick fetchmail[2578]: 5084 messages (5040 seen)
And it downloads them all within a few minutes.
It keeps scanning every few minutes and finds nothing more...There's also nothing in any log 30 minutes later when they all appear.

I'm stuck on where to track down what's holding back the e-mails.  It always seems to be 9 e-mails, and the 

The strange thing is that they don't show up at all in the IMAP mailhome until 30 minutes later, so they must either be in memory or in some sort of spool (no idea where that would be).
-rw------- 1 patrick patrick      7295 Nov 14 18:19 1163557194.H453521P2639.patrick:2,S
...
-rw------- 1 patrick patrick      4551 Nov 14 18:19 1163557194.H165125P2637.patrick:2,S
-rw------- 1 patrick patrick      8476 Nov 14 18:49 1163558971.H690029P2933.patrick:2,S
...
-rw------- 1 patrick patrick     17576 Nov 14 18:49 1163558971.H677840P2931.patrick:2,RS

There's also a chance it's my local SMTP server... not sure how I would know since logs are so sparse.
It's very possible this is an exim4 problem, but it makes even less sense then.

Anyway, I am stuck on tracking this problem down.  It's only reproducible once daily, but it happens every day.

SMTP server: exim4 4.63-8
IMAP server: courier-imap 4.1.1.20060828-2

Debian: etch/testing
Kernel version: 2.6.18.1

-Patrick