For the archives, I found the answer after much Googling. This link
goes over the issue:
http://groups.google.com/group/microsoft.public.exchange.admin/browse_thread/thread/aab7c142b3f2bf71/40fce4d57351a17a%2340fce4d57351a17a?sa=X&oi=groupsr&start=0&num=3
(watch for line wraps).
The client is using Exchange 2003 and a Cyberguard firewall. The
Cyberguard is configured to drop connections if the number of header
lines is > 49. That's right, the number of header lines, not the number
of RCPT TO lines. I guess this helps stop spam. :p
I pointed out the issue with this to my client. They outsource their
firewall maintenance so they're bringing this up with them. :)
M
--
Michael F. Sprague | mfs@???
http://www.saneinc.net | use STD::disclaimer;
System and Network Engineering (SaNE), Inc