When we try and send an email to a large number of people outside of our mail
server (seems as though any more than 22) be get the follwoing bounce back(a
recent development, we were able to do it about a week and a half ago)...
Running Windows 2000 with Exchange 2000 SP3
From: Post Master
Sent: Tuesday, October 25, 2005 7:06 AM
Subject: Delivery Status Notification (Failure)
This is an automatically generated Delivery Status
Delivery to the following recipients failed.
firstname.lastname@example.org and this continues for all 1800 email addresses
(these are our students).
in the attached txt document...
Diagnostic-Code: smtp;554 5.7.1 Command rejected
on a line by itself
However, if I sent an email to say 4 or 5 individuals @syr.edu, it works
fine. When I use POP/SMTP with my SYR.EDU mail address, it goes fine to all
Could it be a Brightmail filter on the receiving side? Could it be a DNS
issue? Any thoughts would be helpful. thanks in advance.