Hey folks, it's been awhile since I've been here but I remember there were a lot of extremely intelligent participants last time, and I see a lot of their names still hanging around, so I thought maybe I would shoot a question your way.

It's not related to PHP directly, but I'm not a member of very many forums anymore, given that most of my time is taken up with work. Hopefully somebody might be able to shed some light anyways.

I'm running a dedicated server on Ubuntu which is at the moment multi tasking between running web services, database, and mail. My POP3 is working wonderfully, but I can't for the life of me figure out what's going wrong with my SMTP. I've scoured the documentation and many many tutorials, but I can't seem to connect.

I have Postfix set up with libsasl for authentication. Everything is configured, and when I telnet to localhost 25 from my shell I get what appears to be an acceptable response;


Connected to localhost.
Escape character is '^]'.
220 mail.k....s.com ESMTP Postfix (Ubuntu)
ehlo localhost
250-mail.k....s.com
250-PIPELINING
250-SIZE 10240000
250-VRFY
250-ETRN
250-STARTTLS
250-AUTH PLAIN LOGIN
250-AUTH=PLAIN LOGIN
250-ENHANCEDSTATUSCODES
250-8BITMIME
250 DSN


I have DNS A records for the mail subdomain, and MX records set accordingly. However, while I can telnet from localhost, I can't reach telnet on port 25 from my local machine. This led me to check my firewall, but my iptables is set to allow connections on port 25;


-[~] iptables -L | grep smtp
ACCEPT tcp -- anywhere anywhere tcp dpt:smtp


So the denial must be happening somewhere in postfix' main.cf, or somewhere else I can't track down. Anybody here got any ideas?