I'm in the process of configuring an exchange server and I've encountered a problem where it's not accepting emails from external domains.
I can email internally and I can email outbound from the OWA, however if I try to email from (say) Gmail, it doesn't appear.
It doesn't, however, give me a bounceback error at Gmail.
I think I've configured the MX/A records correctly for DNS and my ISP confirmed they can telnet using the appropriate information.
I do get an error from mxtoolbox that 'Reverse DNS does not match SMTP Banner' but I've read that it's not important for that to 'match'?
Any ideas?