[CentOS] Sending Email Via Telnet

Tue Oct 16 17:46:45 UTC 2012
John Reddy <linuxpencil at hotmail.com>

> >    netstat -pant|grep ":25"|grep LISTEN
> > to see if any program is listening... output should look like:
> >   tcp 0 0* LISTEN 21493/sendmail
> >
> > guess it'll say 'postfix' or 'master' instead of 'sendmail' on RH6.

]# netstat -pant|grep ":25"|grep LISTEN
tcp        0      0   *                   LISTEN      14058/master
tcp        0      0      *                   LISTEN      14058/master

> How long are you waiting for a response to appear?  Mailers do an
> assortment of reverse-dns lookups and perhaps an ident query to the
> source before responding.   If you firewall these with a 'drop'
> instead of 'reject' you leave the application hanging for fairly long
> timeout.  And some mailers have a config option for an intentional
> delay before their first message and will drop the connection it the
> other end sends first (snmp protocol requires the connecting host to
> wait).    Also, you should have something showing up in
> /var/log/mailllog about the connections.

I can't find anything in there that corresponds to the attempt to send an email. And why would I when there is no communication from the server in my telnet session? The problem appears to be in telnet, not in postfix. Again, this is one of 3 examples of my telnet sessions from 2 emails ago:

[root at mydomain john]# telnet 25
Connected to
Escape character is '^]'.
HELO justtesting
MAIL FROM: testing at gmail.com
RCPT TO: testing at gmail.com
To: testing at gmail.com
From: testing at gmail.com
Subject: testing
Date: Tu, Oct 2012 10:21:11 -0500

Then it hangs. I never get back to a command prompt. There is never any interaction with the telnet program after the initial response. How do I trouble-shoot this?