A third party software was setup to use a relay and was working fine. We recently migrated the server to a new environment and as part of that put it on the Domain and changed the Hostname, though the IP stayed the same.
Now we are getting "550 5.7.1 Client does not have permissions to send as this sender" errors
If we disable the option for Integrated Windows authentication it works though.
Since the relay is set to accept via that IP, which didn't change, is there an option I'm missing that I need to change due to the application now sending from a Domain or some other setting?
Thoughts?
Thanks in advance.