My setup is a very small exchange 2010 environment and I'm toying with the idea to give others a exchange relay outside their network. Most of the end user's local FW are aggressive so trying to navigate the traditional SMTP port (25) outbound to relay an email from a scanner, security camera or alert system is not an option on port 25 and most other non web ports.
I have a exchange 2010 running already but I can build a separate Exchange instance on the same domain and I see an option to only install hub transport that has the receive connector in it. Is it possible to make a receive connector (relay) listen and work on port 443 or 80 in Exchange 2010? If so, what are the best practices to do this; separate ME2010 with hub transport only?
if not possible to make the relay work on 443 or 80, what are other suggestions for clients to use a email relay service for aggressive client firewalls that cannot be modified?
Of course I will filter by IP to be allowed to send; I understand the risk if I opened a anonymous relay to the internet.