To send an email via an SMTP server using the TELNET program, what commands should you use in which order?

To send an email via an SMTP server using the TELNET program, what commands should you use in which order?

• EHLO, DATA, MAIL FROM then RCPT TO
• EHLO, MAIL FROM, RCPT TO then DATA
• DATA, EHLO, RCPT TO, then MAIL FROM
• EHLO, RCPT TO, MAIL FROM then DATA 

 

EXPLANATION

Using telnet to test a mail server is a staple part of being able to diagnose e-mail faults. You must follow a specific protocol order for commands, EHLO first (to introduce your connection and view the available features of the server), MAIL FROM next to specify the sender, RCPT TO thirdly to specify the recipient, and finally DATA, which is followed by the message headers and body.

SOURCE

https://www.port25.com/how-to-check-an-smtp-connection-with-a-manual-telnet-session-2/