Perform a Telnet Test on the SMTP Server from a Microsoft Windows Vista, 7, 8 or 10 OS

NOTE: This solution requires the SMTP Servers connection information. This information would be the IP Address or DNS Hostname of the Mail server, the Port number used to connect, as well as an Email account on the server. Also note that if any Encryption or SMTP Authentication is used on the server, the steps may not work entirely, but can be used to verify connectivity and online status of the mail server.

1. Open the Start Menu.

2. Type Control Panel into the search box and press enter.

3. Go to Programs under Catagory View.

4. Select Programs and Features.

5. Select Turn Windows Features On or Off.

6. Check the Box marked Telnet Client. Select OK.

7. Close the Programs and Features window.

8. Open the Start Menu.

9. Type CMD into the Search Box.

10. Select CMD.exe or Command Prompt.

11. Type TELNET and press Enter.
    
    NOTE: Type the following commands carefully as the backspace key is interpreted as a character by the Telnet Client software.
    
    

12. Type the command open Server Address Port Number and press Enter. (ie: open smtp.gmail.com 25)
    
    NOTE: If connection to the SMTP server is successful, you will receive a reply similar to '220 ESMTP Server'.
    
    

13. Type elho <Domain Name of Mail Server  and press Enter. (ie: ehlo gmail.com)

14. Use the command helo Domain Name of Mail Server instead, if the server returns an error with the ehlo command.
    
    NOTE: The server may require a username and password if SMTP Authentication is enabled. In most cases, the email address is the username, and password is the password of the email account on the mail server.
    
    

15. Type mail from:<Email address of Sender> and press Enter.
    
    NOTE: A response similar to 250 Sender OK means the command was successful.
    
    

16. Type rcpt to:<Email address of Recipent> and press Enter.
    
    NOTE: A response similar to 250 OK - Recipient <Email address of recipient> means the command was successful.
    
    

17. Type data and press Enter.
    
    NOTE: A response similar to 354 Send Data means the command was successful.
    
    

18. Type subject:<subject title> and press Enter. (ie: subject:Test)

19. Enter the message text for the Email to be sent.

20. Type a single period (.) on a blank line followed by pressing Enter to end the message. (ie: . enter)
    
    NOTE: A response similar to 250 Queued mail for deliver means the command was successful.
    
    

21. Type quit and press Enter to disconnect from the Mail Server.