> > netstat -pant|grep ":25"|grep LISTEN > > to see if any program is listening... output should look like: > > tcp 0 0 0.0.0.0:25 0.0.0.0:* LISTEN 21493/sendmail > > > > guess it'll say 'postfix' or 'master' instead of 'sendmail' on RH6. ]# netstat -pant|grep ":25"|grep LISTEN tcp 0 0 209.216.9.56:25 0.0.0.0:* LISTEN 14058/master tcp 0 0 127.0.0.1:25 0.0.0.0:* 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 127.0.0.1 25 Trying 127.0.0.1... Connected to 127.0.0.1. Escape character is '^]'. HELO justtesting MAIL FROM: testing at gmail.com RCPT TO: testing at gmail.com DATA To: testing at gmail.com From: testing at gmail.com Subject: testing Date: Tu, Oct 2012 10:21:11 -0500 Testing . QUIT 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? TIA, John