Can't send email from my mac?

Ben, I don't know if this is relevant, but somewhere in my ActionMailer
searches, I remember someone mentioning that some servers are setup so
that a smtp and pop3 connection were in some way linked. Meaning that
smtp (outbound) would only occur in the timeframe vicinty of a
pop3(inbound) connection.

I think that I found in on the rails wiki, but I dont remember.

and as I did a cursery check I found this (still dont know if it solves
your problem though):

Hope it helps