Postfix-Server behind a DSL-Router

[Frank Elsner]

On Thu, 09 Apr 2015 13:58:48 +0200 Peter Ulrich Kruppa wrote:
> Hello!
> 
> Am 09.04.2015 um 13:20 schrieb Bala Vishwanathan Iyer:
> > Dear Mr. Kruppa
> >
> > I have some futher querries :-
> >
> > 1. Is this server your mail server for your domain. meaning does the
> > mail exchange record for your domain point to this server or some
> > other server.
> >
> > In case it it pointing to some other server say Google mail server or
> > any other hosting provider. Then I would suggest you install something
> > like fetch mail to get mails fro your mail server to your postfix
> > server.
> I believe that is what Frank Elsner was so nice to test from "outside"
> 	# host -t mx pukruppa.de
> 	pukruppa.de mail is handled by 10 mail.pukruppa.de.
> 	# telnet mail.pukruppa.de 25
> 	Trying 217.92.171.227...
> 	telnet: connect to address 217.92.171.227: Connection timed out
> 
> 
> > 2. can you telnet your postfix servers external ip on port 25 from
> > outside your network.
> >
> > If no, then that is the issue.
> Yes, but what can I do? port 25 seems to point to my Fedora box.

Since "telnet localhost 25" shows postfix listening and you tell us 
"port 25 seems to point to my Fedora box" (note the "seems"!)
the question arises: 
      
         Is postfix listening on ALL interfaces? 

Assumed the port forwarding is ok but postfix only listening
on 127.0.0.1 the case is clear.


--Frank