How to Send Test Email via Telnet

When troubleshooting email issues, it may be useful to send emails directly from the email server using the telnet application. This article walks you through step-by-step how to send an email from an email server.

NOTE: This example uses fictitious domains and email addresses. Be sure to replace with your own.

Use your favorite telnet utility. Either the utilities built into Windows or Linux or the popular Putty.

Type these commands to establish the connection and set the to and from addresses:

telnet 25
mail from: [email protected]
rcpt to: [email protected], [email protected]

To write the message, type data, followed by the subject and message. Follow it with a period on it’s own line and press enter:

Subject: test email

Hello, this is a test email via telnet.



Type quit to exit telnet. The email will be sent immediately or will give error that can aid in troubleshooting.


Jason works as a project specialist at an IT MSP in Pennsylvania, USA. He's an IT/security professional with 20 years experience.