I never get an email notification when I email someone or when I've bought from the shop. Is that likely to be your end or my end? I get notifications generally when shopping on-line etc. I'm on AOL and use McAfee firewall.
I'm having probs with this too. My email system went down at the beginning of the month, so was bouncing everything. I assume you've got a clever dead address detection system. What do i need to do to sort it out?