Sending email through telnet can be a useful tool when testing mail functionality, testing for open relays, or sending mail from admin scripts. This is something I don’t use often enough, so I’ve created this blog as a reminder.
- Open the cmd prompt.
- Type telnet <server> 25
- Type HELO <domain>
- Type MAIL FROM: <email address>
- You may get a message saying “250 ok“
- Type RCPT TO: <email address>, <email address>, <email address>, etc.
- You may get another message saying “250 ok“
- To write the message, type DATA, followed by your message.
- To enter a Subject, type SUBJECT:, followed by your message.
- To end the message, put a period on a new line by itself and press Enter.
- Type QUIT to exit Telnet.
Source: http://www.wikihow.com/Send-Email-Using-Telnet