Getting a "reason: 553 sorry, relaying denied from your location xxx.xxx.xx.xxx" error on messages sent to def.com [example domain]
I have an SBS server setup for domain abc.com. I want all of my users to be able to receive mail for their name at def.com, so I setup my A name DNS entry on def.com to point to the IP address of my server, same as abc.com is set up. I added def.com to my recipient policies and applied them, and I tried allowing relaying from xxx.xxx.xx.xxx, but I get the same error. Any ideas?