Telnet is an internet protocol providing command line access to servers. Telnet can be used to connect to email mail servers and send emails. This article will show you how.
Telnet comes with most Linux and Mac systems. On Windows machines you must enable telnet in the control panel programs and features section.
Connecting to a mail server
First step is to open a terminal or command line (such as powershell). Then type:
Here we connect to the MailSlurp email server but you can replace mx.mailslurp.com with any SMTP server. The second argument (2525) is the port. Typically, email servers run on port 25 or 2525. Use dig to lookup DNS nameservers if you don't know an SMTP server host.
Once connect you must say hello using the
If successful you will see a reply such as:
Sending a message
Mail from command
Telnet is a step-by-step process. You must instruct the server who is sending the email and to whom. Say you are sending an email to the server from firstname.lastname@example.org, run the following command:
The server will respond with OK if it accepts your mail sender:
Next you must specify the recipient of the email using
The server will respond:
Data and subject
Next we can set the subject and the body of the message.
For the data we use the
command and end our message with a new line and full stop.
What about receiving mail?
You can also read emails with telnet, provided you have login credentials. Use the
commands to login with your SMTP username and password.
once logged in to list emails. Each email is given a number. Use the number to read each message using the
Retr (for retrieve)
to view the email by giving the number of the email that you obtained from the list.
BCC and CC
For more options see the BCC and CC SMTP guide.