I have three almost identical SBS 2008 server setups and one of them isn't allowing me to send e-mail remotely from, say, an iPhone.
I can send e-mail on the network from Outlook via the Exchange Server both internally and externally.
Outside on the net I can send e-mails that will be received by users on this network, and they can reply.
Ports 25, 80 and 443 are open on the firewall and forewarded to the server.
The certs including autodiscover have been created and are in place on the server.
The Exchange Management settings appear to be identical to the working servers. Ditto services and firewall settings.
BUT if I try and set up an account on my iPhone it spends an age trying to verify the account. In short it doesn't seem to be allowing the remote login. I have even created accounts with ultra short names so make sure it's not a spelling mistake. Any ideas?
If I do a telnet 25 into the server when I do the MAIL FROM: command it works but when I do the RCPT TO: I get an 501 5.1.3 Invalid Address. In fact it's an e-mail address on that server so it must. Does that give any clues?