How to use Telnet to test an Internet Mail connection

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This article describes how to use the Telnet terminal program to test a connection to a POP3 server.

The following topics are covered in this article:

  • Establishing a Telnet session to the POP server
  • Using POP commands in a Telnet session


Establishing a Telnet Session to the POP Server

Telnet is a terminal emulation program supplied with Microsoft Windows. With Telnet, you can establish a host session to a server using one of several emulation types.

To establish a Telnet session, follow these steps:
  1. Use your Dial-up Networking connection to connect to the Internet through your ISP.
  2. Click the Start button, point to Programs, and then click MS-DOS Prompt. In Microsoft Windows NT, this item is labeled Command Prompt.
  3. In the MS-DOS window, type the following:
    telnet <POP server name or IP address> 110
  4. Press the ENTER key. The Telnet window appears and displays a welcome message. This message will be preceded by +OK and will vary depending on the software installed on the POP Server.
NOTE: The default port defined for communications to a POP server is 110. Your ISP may have defined a different port for your server. If there is difficulty establishing a connection through the default port, consult the ISP for information about the server configuration.

Additionally, you may need to enable Local Echo to see characters as they are typed. To set local echo in a Telnet session, follow these steps:
  1. On the Terminal menu, click Preferences.
  2. In Terminal Preferences, click to place a check at Local Echo." Click OK.
If, when you type, each letter that you type appears twice, use the above procedure to deactivate Local Echo.

Using POP Commands in a Telnet Session

This section outlines some basic POP commands that you can use to verify the connection and condition of your mail box on the POP server. Before beginning sending commands with Telnet, you may want to define a log file to capture the text of the session. To capture a Telnet log, follow these steps:
  1. On the Terminal menu, click Start Logging.
  2. In Open Log File, type a file name for the current log. Note the folder location of the file. The default location is the Windows folder.
  3. Click OK.
Telnet will capture the current session as you enter commands. The log will close when you quit Telnet. You may cancel the log at any time during a Telnet session by clicking Stop Logging on the Terminal menu.

NOTE: Telnet does not have a full-featured text editor. If you make a mistake and then backspace to correct the mistake, the command may not be recognized. In most cases you will receive a command error. Reentering the command is necessary in these cases. If you make a mistake when entering the password, however, most servers will terminate the session, and you must establish a new session.

Telnet Commands

  • USER
This command identifies you as a registered account on the server. After you see the server welcome message mentioned above, type USER <account name> After entering the USER information, the server will return a line that reads, "+OK Password required for <account name>."
  • PASS
Type PASS <your password> If the password is accepted, the server will return a line similar to: "+OK <account name> has <n> message(s) (MMMMM) octets", where <n> is the number of messages stored in your mailbox on the server and (MMMMM) is the total size of all messages.
  • LIST
Type LIST at the prompt. The server will return "+OK <n> messages <MMMMM> octets), a list of the messages including their numbers, and the individual message sizes.

  • RETR
This command will retrieve the text of a message. For example, if you wish to retrieve message number 4, type at the prompt, "RETR 4."

  • DELE
This command allows you to delete a message from the POP server. To delete a message enter DELE <n>, where <n> is the message number determined from the LIST command. For example, to delete message number 4, enter the command "DELE 4."

  • QUIT
This command permits you to quit the Telnet session.

IMPORTANT: The DELE command should be used with care and in extreme cases where a specific message is blocking mail delivery. It is strongly recommended that you retrieve the text of the message into a log file as described above before attempting to delete it.


For additional information on configuring a Dial-up Networking connection to the Internet in Windows 95, click the following article number to view the article in the Microsoft Knowledge Base:
138789 How to connect to the Internet in Windows 95
For additional information on configuring a Dial-up Networking connection to the Internet in Windows NT, click the following article number to view the article in the Microsoft Knowledge Base:
156569 How to connect to Internet service providers from Windows NT


Article ID: 187785 - Last Review: January 23, 2007 - Revision: 1.2
  • Microsoft Outlook 97 Standard Edition
kbhowto KB187785
Retired KB Content Disclaimer
This article was written about products for which Microsoft no longer offers support. Therefore, this article is offered "as is" and will no longer be updated.

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