Lately my emails have been bouncing back from friend's account, that never use to be a problem. I don't think it's my server. My fear if I have some bug that their firewall is rejecting. How should I address this problem?
Lately my emails have been bouncing back from various of my friend's accounts- in the past there was never a problem. It's not my server - my fear is I have some bug and their firewall is rejecting me. How can I find out what the problem is?