XFOR: Telnet to Port 25 of IMC to Test IMC Communication

• Microsoft Exchange Internet Mail Connector, version 4.0
• Microsoft Exchange Internet Mail Service, version 5.0

SUMMARY

This article describes how to "Telnet" to port 25 on the computer running the Microsoft Exchange Internet Mail Connector (IMC) in order to troubleshoot communication problems between a Microsoft Exchange Internet Mail Connector (IMC) and another IMC or hosts.

MORE INFORMATION

Before starting the Telnet session, find the Full SMTP address of the Microsoft Exchange user (something similar to User@Site.Domain.Com) and the IP address of the Microsoft Exchange Server running the IMC (something similar to 125.125.0.4).

NOTE: this information can be used to TELNET to other hosts by simply substituting the IP for the IMC with the IP address of the host and the Microsoft Exchange user's SMTP address with one valid for the host you are connecting to.

Be sure the IMC is started via the Services applet in the Control Panel. Also note that some telnet applications require you turn on local echoing in order to see the commands you are typing.

Follow the steps below to make sure communication between the Host and IMC is working (note: press <Enter> after each line typed):

1. Start a TELNET session using the following command:

          Telnet 125.125.0.4 25 (substituting the above IP)
   

       If this works, you will see this response from the IMC:
   

          220 site.company.com Microsoft Exchange Internet Mail
          Connector 4.0.xxx.xx
   

       where xxx.xx is 837.3 for RTM, and 838.14 for SP1.
   

2. Begin communication by typing the following command:

          HELO test.company.com
   

       You should see this response:
   

          250 OK
   

3. Type the following command to tell the IMC who the message is from:

          MAIL FROM:<Admin@po1.company.com>
   

       You should get the following response:
   

          250 OK - MAIL FROM <Admin@po1.company.com>
   

4. Type the following command to tell the IMC who the message is to

       (use a valid Microsoft Exchange recipient's SMTP address).
   

          RCPT TO:<User@Site.Domain.Com>
   

       You should see this response:
   

          250 OK - Recipient <User@Site.Domain.Com>
   

5. Type the following command to tell the IMC you are ready to send

       data:
   

          DATA
   

       You should see this response:
   

          354 Send data.  End with CRLF.CRLF
   

6. Type the following command to add a subject line:

          Subject: test message
   

       and press the Enter key twice.
   

       You will not see a response from this command.
   

       Note: The two Enter commands conform to RFC 822, which states 
       that 822 Commands must be followed by a blank line.
   

7. Type the following command to add message body text:

          This is a test message
   

       You will not see a response from this command.
   

8. Type a period at the next blank line and press the ENTER key.

       You should see this response:
   

          250 OK
   

9. Close the connection by typing the following command:

          QUIT
   

       You should see this response:
   

          221 closing connection
   

1. Sign into the Microsoft Exchange client mailbox for the user you

       sent the message to in Step 4 above. If your test message is there,
       then the inbound IMC communication is working.