Okay, this is still a little over my head, but I want to hang in there. I could definitely remove the domain name from the main.cf even though I don't understand virtual users. My guess would be anyone who doesn't have an actual user account on my server, i.e. those Drupal users requesting a password or registering.
On the other hand, I monitored the mail.log while requesting a new password, and it showed something interesting:
Jan 11 13:57:07 debian postfix/pickup: 20152F6268: uid=33 from=<www-data>
Jan 11 13:57:07 debian postfix/cleanup: 20152F6268: message-id=<20100111185707.20152F6268@fingertip-realm.webhop.info>
Jan 11 13:57:07 debian postfix/qmgr: 20152F6268: from=<email@example.com>, size=1148, nrcpt=1 (queue active)
Jan 11 13:57:07 debian postfix/qmgr: warning: connect to transport smtp: Connection refused
Jan 11 13:57:07 debian postfix/error: 20152F6268: to=<firstname.lastname@example.org>, relay=none, delay=0.31, delays=0.26/0.02/0/0.03, dsn=4.3.0, status=deferred (mail transport unavailable)
I know I left the domain name in there this time because, what, I don't
want visitors?? It's just a blank message board though.
Alright, what I did was change the
scache unix - - - - 1 scache
scache unix - - n - 1 scache
and restarted the postfix daemon that's in init.d, but it didn't make a difference until I put case-sensitive letters in the captcha. Never can tell with those captchas unless they're explicit. This one, Mollum, was telling me an e-mail was sent no matter what I put in there. The difference was it left out the line about refused smtp connection, but four minutes later, it spouted all those original four lines out again. Then, I took out the domain name from main.cf and restarted the postfix daemon again, but same errors; so I'm reverting back both files. I also rebooted after making the changes, but that didn't work.
PS Should the myhostname be my server's hostname or the web domain name?