Article taken from AOL.COM

To manually perform a mail transaction through telnet, perform the following steps:

1. From a Command prompt, Type:
   
   telnet remotehost.com 25
   This specifies to telnet to port 25 on an AOL mail host.
   
   220
   The mail host identifies itself. This should be accompanied by several lines of introductory text.
   
   
2. Type:
   
   HELO yourdomainname.com
   where yourdomainname.com
   specifies your domain.
   
   250 OK
   followed by the server you are connecting to.
   
   
3. Type:
   
   MAIL FROM:
   where you@hostname.com
   indicates the address the mail should appear to be from.
   Note: You must include the equality(< >) signs
   
   250 OK
   
   
4. Type:
   
   RCPT TO:
   Note: You must include the equality(< >) signs
   
   250 OK
   
   
5. Type:
   
   DATA
   
   START MAIL INPUT, END WITH "." ON A LINE BY ITSELF
   
   
6. Type:
   
   FROM:
   
where you@hostname.com
indicates the address the mail should appear to be from.


7. Type a brief message, followed by . (Type a period on a line by itself, then hit ENTER.)
   
   250 OK