External connection to Postfix problem‏

[Gary Brinker]

> Imre Gergely


> > The issue is that I can telnet into it internally with no problem but
> > cannot reach it externally. I hooked up wireshark and if I'm
> > interpreting it correctly I do find the initial SYN come in but no
> > connection is established. My reading suggests that I may have an

> I would check some basics first.
>  
> Is postfix listening on the external IP address? If not, see
> inet_interfaces in main.cf (man 5 postconf)
>  
> sudo netstat -nlp |grep master |grep tcp
>  
> Is the firewall really off? Try this:
>  
> iptables -I INPUT 1 -p tcp --dport 25 -j ACCEPT
>  
> This should accept connections to the SMTP port from anywhere.
 
 Am I interpreting this correctly that it should be listening on any IP without any firewall rules?

> sudo netstat -nlp |grep master |grep tcp
 tcp 0 0 0.0.0.0:25 0.0.0.0:* LISTEN 4375/master
 tcp6 0 0 :::25 :::* LISTEN 4375/master
  
> sudo iptables -L
 Chain INPUT (policy ACCEPT)
 target     prot opt source               destination
 LOG        tcp  --  anywhere             anywhere             tcp dpt:smtp   LOG level warning
  
 Chain FORWARD (policy ACCEPT)
 target     prot opt source               destination
  
 Chain OUTPUT (policy ACCEPT)
 target     prot opt source               destination 		 	   		  
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