I'm experiencing a very strange issue with Squirrelmail. It was working fine out of the box for three years, and now suddenly it started producing bizarre errors with attachments.

When I click on a message attachment , it will wait for 30-50 seconds and then begin to download a file with the CORRECT filename, but after it's done downloading, I can see that it is actually an HTML file with the error message:


ERROR:
ERROR : Unknown imap response.
Query: FETCH 1451 BODY[3]
Server responded:

---
I can still access all messages over Outlook/Thunderbird perfectly.

I was able to even telnet into the imap server and look at the content of the message in the mailbox with out any issue. No problems when I told the imap server to fetch the body text of the message -- very fast response and then it went back to a prompt.

I'm wondering what squirrelmail is doing. The imap server seems to respond as expected to the fetch command.


Here are my specs.

Linux: Red Hat Enterprise Linux 3
IMAP SERVER: courier-imap-3.0.1-1psa.rhel3
SERVER C/P: Plesk 7.0.2
APACHE Server version: Apache/2.0.46 2.0.46-32.ent
PHP 4.3.2-37.ent
QMAIL 1.03-rhel3.build040408.00
SQUIRRELMAIL version 1.4.2

The only recent change we did was cleaning up qmail's remote queue of messages after some spammer managed to queue 5.000 messages for delivery from our server. we used qmHandle to clean up the queue.

I honestly can not understand what would be the error here.

The issue was also discussed on SWSoft's forums here:
http://forum.swsoft.com/showthread.php?p=105744#post105744

any help would be greatly appreciated. theplanet suggests that I upgrade my old 7.0.2 plesk but I would really like to avoid it.