I'm trying to set up PHP on a Windows Server 2008 machine running both IIS7 and Exchange 2010, and no matter what I do, it will not relay messages outside of the domain.
I.e.: I telnet to
localhost 25, do the
HELO/MAIL FROM:/RCPT TO: dance. Any domain ending in my local domain works; any with elsewhere as domain receive a
550 5.7.1 Unable to Relay error.
If I set
* as an Accepted Domain, everything starts working, mails relay, all of it works great. However, this is clearly problematic -- I'd really like to not turn my client's server into an open relay (verified via Abuse.net's relay checking tool).
How does one enable open relaying from only localhost in Exchange 2010?