I am quite stuck with my postfix/smtp configuration on my CentOS machine.
I setup a mail dns mail.domain.tld, configured in the postfix main.conf file and tested
locally on the server by connecting to
$telent mail.domain.tld 25
This gives me a response and it's possible to send e-mails from the mail server it self.
Now, I want to use the mail server in my e-mail client but I cant get a connection with the server, if i test a telnet connection from my local desktop it's been refused by the server.
I know this should be something like a firewall, there is iptables running but I added ports to be accepted, I added + saved + restarted iptables but no port 25 or 587 (also configured from the postfix master.conf) wont work from outside the server.
(telnet 587 also not working from the server locally).
# lsof -ni tcp:25
COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
master 27179 root 12u IPv4 52473467 0t0 TCP *:smtp (LISTEN)
master 27179 root 13u IPv6 52473469 0t0 TCP *:smtp (LISTEN)
# netstat -an | grep LIST
...
tcp 0 0 0.0.0.0:465 0.0.0.0:* LISTEN
tcp 0 0 0.0.0.0:25 0.0.0.0:* LISTEN
...
# iptables -L
Chain INPUT (policy DROP)
target prot opt source destination
ACCEPT tcp -- anywhere anywhere tcp dpt:smtp
I can deliver more outputs if needed!
Thanks in advance
Best Answer
You should be sending outgoing mail from your desktop on port 587, the submission port, not port 25 (which is meant for transferring mail between SMTP servers). Make sure your
/etc/postfix/master.cf
has thesubmission
section enabled.