[CentOS] Sending Email Via Telnet

on 10/16/2012 8:16 AM John Reddy spake the following:
> 
> 
>> Something isn't quite right with your setup.  When you do the "HELO" command, the server should reply with something.  For example:
>>
>> ==
>> $ telnet smtp.comcast.net 25
>> Trying 76.96.40.155...
>> Connected to smtp.comcast.net.
>> Escape character is '^]'.
>> 220 omta12.emeryville.ca.mail.comcast.net comcast ESMTP server ready
>> HELO comcast.net
>> 250 omta12.emeryville.ca.mail.comcast.net hello [69.24.1.7], pleased to meet you
>> ==
>>
>> Does the mail server ever return anything back to you?
> 
> No. Never. How do I trouble-shoot this?
> TIA,
> John
>  		 	   		  
> 
Do you have anything like greylisting or greetpause running?