Email Not Listening on Port 25
The line, in /etc/postfix/master.cf, for 'smtp inet . . .' had been commented out. Removed the comment, restarted Postfix, all good.
END EDIT
I am trying to set up an email server per the excellent "Email with Postfix, Dovecot, and MySQL" article.
Unfortunately, while I can send email via a remote client, I cannot receive email. Efforts to send email to an account on the server get this error message:
The recipient server did not accept our requests to connect. Learn more at
[(10) mail.hammeringbits.net. [23.239.10.92]:25: Connection refused]
Searching on this lead me to a Linode article suggesting ports were the problem.
netstat -ntlp
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0 0 127.0.0.1:8891 0.0.0.0:* LISTEN 4003/opendkim
tcp 0 0 0.0.0.0:993 0.0.0.0:* LISTEN 4391/dovecot
tcp 0 0 0.0.0.0:995 0.0.0.0:* LISTEN 4391/dovecot
tcp 0 0 127.0.0.1:3306 0.0.0.0:* LISTEN 3804/mysqld
tcp 0 0 0.0.0.0:465 0.0.0.0:* LISTEN 4356/master
tcp 0 0 23.239.10.92:53 0.0.0.0:* LISTEN 5854/named
tcp 0 0 127.0.0.1:53 0.0.0.0:* LISTEN 5854/named
tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN 3638/sshd
tcp 0 0 127.0.0.1:5432 0.0.0.0:* LISTEN 28746/postgres
tcp 0 0 127.0.0.1:953 0.0.0.0:* LISTEN 5854/named
tcp6 0 0 :::443 :::* LISTEN 3100/apache2
tcp6 0 0 :::993 :::* LISTEN 4391/dovecot
tcp6 0 0 :::995 :::* LISTEN 4391/dovecot
tcp6 0 0 :::80 :::* LISTEN 3100/apache2
tcp6 0 0 :::465 :::* LISTEN 4356/master
tcp6 0 0 :::53 :::* LISTEN 5854/named
tcp6 0 0 :::22 :::* LISTEN 3638/sshd
tcp6 0 0 ::1:5432 :::* LISTEN 28746/postgres
tcp6 0 0 ::1:953 :::* LISTEN 5854/named
I don't see any line for port 25 here, which seems suspicious.
I don't think the firewall is the problem:
iptables -L -n -v:
Chain INPUT (policy ACCEPT 453M packets, 30G bytes)
pkts bytes target prot opt in out source destination
Chain FORWARD (policy ACCEPT 0 packets, 0 bytes)
pkts bytes target prot opt in out source destination
Chain OUTPUT (policy ACCEPT 417M packets, 69G bytes)
pkts bytes target prot opt in out source destination
So far as I can tell this isn't blocking anything.
So I think the problem is that Postfix (Dovecot?) aren't listening on port 25. The setup article doesn't have any reference to setting any particular option to port 25, so I presume Postfix (Dovecot?) listens to port 25 by default. But it doesn't seem to be doing so here.
I suppose I could have done something in configuration that told Postfix to let Dovecot do the listening on 25, and missed the configuration to make Dovecot actually do that listening.
How do I debug this?
Any help would be appreciated. Thanks.