This article provides a quick summary of the common SMTP commands and sequence used by the SMTP Protocol to transfer email via the TELNET command.  Of course, your SMTP server must be configured to allow for mail relaying.

Step 1

Open a command prompt and connect to the SMTP server using TELNET over port 25. This will open a TELNET window, and you should expect a response such as: The response will vary depending on the SMTP server software.  However, the 220 response indicates that you made a successful connection.

Step 2

The next step is to identify yourself.  If your computer name is IT1.itgeared.com, then type in the following: If the server accepts your input, you should expect the following in return: The response will also vary from server application type and version.

Step 3

Next, provide the mail from the address. Depending on your mail server’s security settings, the mail form may be required to be from a certain domain suffix: The server should respond with something like:

Step 4

Provide the server to who you want to send the e-mail. You can enter any e-mail address. If there is some problem with the recipient-address, your mail will bounce. The response should be:

Step 5

The next step is to tell the server data is coming for the body of the message: The server will then notify you that it is now OK to provide the data.

Step 6

Type in the message you want to be included in the body: When you are done typing in the message body, hit the enter key, then type in a ., then hit the enter key once again.

Step 7

If you want to send out another message, repeat steps 4-6, otherwise, type in quit: The server will respond with: That’s it! You have successfully sent mail via the TELNET command.