It's possible that I am wrong but I got this feeling that some external users maybe able to use my exchange server.
Currently I have 3 receive connectors and one send connector.
Send connector doesn't have any specific restrictions in exchange 2010 SP1.
My receive connector is listening to anything ( all IPv4 IP addresses ) and following permissions group are enabled.
Legacy exchange servers
Is this okay ?
I want to make sure that our email server never ends up to spam black list !