telnet to mail server from outside does not get 220, telnet from inside works

[brad davison]

> Date: Mon, 12 May 2008 17:49:07 +0200
> From: wojtek at wojtek.tensor.gdynia.pl
> To: demonichandextensions at hotmail.com
> CC: freebsd-questions at freebsd.org
> Subject: Re: telnet to mail server from outside does not get 220, telnet from inside works
> 
> > Trying ::1...
> > Connected to localhost.xxxxxxxxx.com.
> > Escape character is '^]'.
> > 220 email.xxxxxxxxx.com ESMTP Sendmail 8.13.8/8.13.8; Mon, 12 May 2008 10:01:39 -0400 (EDT)
> >
> >
> >
> > But if I try the same thing from 'outside' the firewall I get:
> >
> > %telnet email.xxxxxxxxxxxx.com 25
> > Trying 67.x.x.x...
> > Connected to email.xxxxxxxxxxx.com.
> > Escape character is '^]'.
> > Connection closed by foreign host.
> >
> >
> sendmail try to connect to port auth of remote machine. your firewall 
> probably blocks it just by dropping packets, so it tries until timeout
> 
> telnet from outside, wait few minutes and you will get a prompt.
> 
> change your firewall rules to fix it
> _______________________________________________


You get the prize.  

We have a Cisco ASA, and everything works on port 587, but port 25 has cisco's 'Application Inspection' or something that I need to figure out how to turn off.

Thanks for the attention.

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