2004Q2 POP3 misbehaviour under load

Question

Hi,
while running some tests on 2004Q2 I've encountered a strange behaviour of the POP3 server, which looks like a bug.
Setup is the following:
Sun Java(tm) System Messaging Server 6.1 (built Apr 28 2004)
libimta.so 6.1 (built 13:10:36, Apr 28 2004)
SunOS srvmsg01 5.9 Generic_117171-07 sun4u sparc SUNW,Sun-Fire-V440
There are 6 mail partitions managed by Veritas Cluster 4, but this occurs even when accessing one single account in plain POP3, without any other activity on the system (neither HTTP, nor SMTP nor IMAP not reconfiguration).
UserDS is on another machine and always accessible. LDAP access log shows no change in lookups for the userid provided in the POP3 USER command.
After a good amount of connections (say >256) and a good amount of messages downloaded (say >2GB, >16000msgs) in trunks of 100msgs/connection the POP3 server does not recognize anymore the user id, and appends a domain to the user.
A "General Error" message is logged.
This excerpt from the pop log (debug mode) might explain better what I mean (no lines were deleted in this excerpt):
[01/Apr/2005:12:34:10 +0200] srvmsg01 popd[10086]: Account Information: connect [158.101.x.x:48190]
[01/Apr/2005:12:34:10 +0200] srvmsg01 popd[10086]: Account Information: login [158.101.x.x:48190] testrw210 plaintext
[01/Apr/2005:12:34:13 +0200] srvmsg01 popd[10086]: Account Notice: close [158.101.x.x:48186] testrw204 2005/4/1 12:34:02 0
:00:11 1930 16121130 1
[01/Apr/2005:12:34:13 +0200] srvmsg01 popd[10086]: Account Information: connect [158.101.x.x:48192]
[01/Apr/2005:12:34:14 +0200] srvmsg01 popd[10086]: General Error: Failed to convert message for [email protected]
(lang=en).
[01/Apr/2005:12:34:14 +0200] srvmsg01 popd[10086]: Account Information: login [158.101.x.x:48192] [email protected] plaintext
[01/Apr/2005:12:34:14 +0200] srvmsg01 popd[10086]: Account Notice: close [158.101.x.x:48192] [email protected] 2
005/4/1 12:34:13 0:00:01 49 306 1
Once the General Error is issued, a mailbox user/[email protected]/INBOX is created on the primary filesystem in parallel to user/testrw204/INBOX. The former is accessed thereafter, unbtil the pop3 service is restarted.
otherdomain.com is defined in our DC Tree, and AFAIR it was created last.
I've been able to reproduce this behaviour 5 times, but haven't been able to find a common condition to all cases.
Thanks for reading so far!

Answer 1

There are several possibilities . . .
I doubt that the "general error" has anything to do with what you're seeing.
You should certainly apply the latest 6.1 patch to your system, just as a general rule:
116568-99
The "general error" would have to do with a particular message, and not with authentication.
I have seen issues when a user located in the default domain suddenly gets a new mailbox in user@domain rather than "user". These usually were caused by confilicting domain definitions in LDAP (not an ldap problem, but an error in setting the system up).