How to use Telnet to send mails?
Commands on how to send email using telnet
1. Open a connection to your email server.
Telnet mail.server.net 25
2. You should see a reply back from your server
220 mail.server.net Microsoft ESMTP MAIL Service, Version: 5.0.2195.6713 ready
at Tue, 2 Sep 2108 10:10:16 -0400
HELO mail2.server.net <– where mail2.server.net is where you are sending the email from
MAIL FROM: email@example.com
RCPT TO: firstname.lastname@example.org
DATA <– this will enable you to type your message
7. Enter a period on its own line will exit out
QUIT <– this will end the telnet session