KnowledgeBase Archive

An Archive of Early Microsoft KnowledgeBase Articles

View on GitHub

Q173903: XFOR: Changing the TCP Port Used for SMTP Mail

Article: Q173903
Product(s): Microsoft Exchange
Version(s): winnt:4.0,5.0,5.5
Operating System(s): 
Keyword(s): kbsetup kbtshoot kbusage
Last Modified: 21-APR-1999

-------------------------------------------------------------------------------
The information in this article applies to:

- Microsoft Exchange Server, versions 4.0, 5.0, 5.5 
-------------------------------------------------------------------------------

SUMMARY
=======

This article tells you how to configure the Microsoft Exchange Server Internet
Mail Service (IMS) to use a TCP port other than port 25 to receive SMTP mail.
This is a function of the TCP/IP protocol and is controlled by the entry in the
Services file in the Winnt\System32\Drivers\Etc directory. This change is
required if you are using the new Mail Virus Scan from Symantec; the Symantec
product requires forwarding to the SMTP gateway by way of a port other than port
25.

MORE INFORMATION
================

1. Edit the Services file, Winnt\System32\Drivers\Etc\Services, to specify the
  port used for SMTP.

  The following example, an excerpt from the Services file, shows removing SMTP
  from port 25 and enabling SMTP on port 17. Port 17 is normally used for
  'qotd' (quote of the day) service.

        smtp 17/tcp mail
        #qotd 17/tcp quote
        #qotd 17/udp quote
        chargen 19/tcp ttytst source
        chargen 19/udp ttytst source
        ftp-data 20/tcp
        ftp 21/tcp
        telnet 23/tcp
        #smtp 25/tcp mail
        time 37/tcp timserver

2. Telnet ip_address or server_name 17 to verify that the Internet Mail Service
  is indeed listening on tcp port 17.

Mail Virus Scan is manufactured by Symantec, a vendor independent of Microsoft;
we make no warranty, implied or otherwise, regarding this product's performance
or reliability.
======================================================================
Keywords          : kbsetup kbtshoot kbusage 
Technology        : kbExchangeSearch kbExchange500 kbExchange550 kbExchange400 kbZNotKeyword2
Version           : winnt:4.0,5.0,5.5
Issue type        : kbinfo

=============================================================================

THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY.