I have an exchange system that works for the most part, however, from time to time I get an NDR stating that it is unable to relay for the public IP address of the server. Below I have posted the NDR that is received. The public IP address is that of the exchange server as forwarded from the firewall. Why would Exchange get this error when sending out its own public IP address? Sometime I also get the error Not Local Host.
One Note on this is that I have a firewall with two internet connections. I have MX records configured for both public IP addresses but the primary IP has a value of 10. Should it not all ways use the mail record unless mail is not available and then go to ms1, and so on? Could this be causing the relay error?
'firstname.lastname@example.org' on 6/23/2008 11:00 AM
There was a SMTP communication problem with the recipient's email server. Please contact your system administrator. <mail.validpublicdomain.com #5.5.0 smtp;550-mail.validpublicdomain.com [188.8.131.528] is currently not permitted to relay>
validpublicdomain.com MX preference = 10, mail exchanger = mail
validpublicdomain.com MX preference = 20, mail exchanger = ms1.
validpublicdomain.com MX preference = 30, mail exchanger = smtp
ms1.validpublicdomain.com internet address = 184.108.40.2068
smtp2.sea.eschelon.com internet address = 220.127.116.11
mail.validpublicdomain.com internet address = 18.104.22.1688
Note I have changed the IP addresses to random numbers.