We have recently moved from Exchange 2003 to Exchange 2007. There are lots of internal apps and tools running on different servers in our organization which sent mail alerts and reports to the concerned teams.
All tools/apps are sending alerts except one, although i have added its IP to my HUB transport servers anonymous relay like i did for others, below is the error i got in logs:
"javax.mail.MessagingException: Failure sending HELO command to SMTP server"
it was working fine when we were on exchange 2003.
When i am trying to telnet my HUB transport on port 25 from the server catering that app, it letting me thru with 220************ response.