In this tutorial you will see how you can spoof an email from anyone to anyone using SMTP and telnet. Although, a lot of mail servers are smart about this and reject emails sent from this. My experiments have shown that a lot of servers still accept these messages due to inadequate security.
The first thing to do is finding the MX record for the server you will be spoofing from.
dig mx example.com
Look for the answer section in the response, and you should see a resolved domain name (sometimes this has the word “protection” in it, nothing to worry about!).
Next, we will use telnet to login to the server. Port 25 is for SMTP.
telnet example.com 25
At the prompt, you will have to enter the following commands.
EHLO abcd MAIL FROM: <email@example.com> RCPT TO: <firstname.lastname@example.org> DATA from: <email@example.com> to: <firstname.lastname@example.org> subject: Random body: Random again .
EHLO, MAIL FROM, RCPT TO and DATA are commands.