4.3.0 lmtpd: Virtual memory exhausted - problem :(

[Pascal Gienger]

I am using Cyrus IMAP 2.1.12 (Suse Linux package, no source install allowed 
here), and we see some errors from lmtpd saying "Virtual memory exhausted".

ulimits are unlimited for every resource (no limit), and there are 4 
Gigabytes of swap used by 5% and 2 Gigabytes of RAM.
System is GNU/Linux 2.4.20-64GB.

Our postfix mailer tries to deliver a message to a local lmtpd (Cyrus 
system) and here is the result:

Jun 30 07:38:43 rauch postfix/lmtp[3129]: EC7FD4400088: 
to=<[EMAIL PROTECTED]>, 
orig_to=<[EMAIL PROTECTED]>, 
relay=/mail/cyrus/socket/lmtp[/mail/cyrus/socket/lmtp], delay=142730, 
status=deferred (host /mail/cyrus/socket/lmtp[/mail/cyrus/socket/lmtp] 
said: 421 4.3.0 lmtpd: Virtual memory exhausted (in reply to end of DATA 
command))

Has anybody seen this already? Which memory lmtpd claims to be exhausted?
With no process limits at all?
Pascal
--
Pascal Gienger, Kanzleistrasse 14, D-78462 Konstanz
Postfix+SASL-AUTH+LDAP Solaris 8:   http://pgienger.de/postfix/