Configuring sendmail on Jaguar
Subject:   send via
Date:   2003-04-14 05:43:43
From:   anonymous2
Response to: send via

Is the Apple firewall on? Either open port 25 or turn the firewall off entirely. I turned the firewall off 'cause my ISP provides NAT translation at their gateway. Good security, but a pain if you want to reach your machine from the outside.
Don't forget to reboot. Yes, sounds like Windoze but is the sure way to restart everything.