KnowledgeBase Archive

An Archive of Early Microsoft KnowledgeBase Articles

View on GitHub

Q258140: XFOR: Error Message Occurs When You Enable a User to Relay

Article: Q258140
Product(s): Microsoft Exchange
Version(s): 5.5 SP2
Operating System(s): 
Keyword(s): kberrmsg
Last Modified: 06-AUG-2002

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

- Microsoft Exchange Server, version 5.5 SP2 
-------------------------------------------------------------------------------

IMPORTANT: This article contains information about modifying the registry. Before you 
modify the registry, make sure to back it up and make sure that you understand how to restore 
the registry if a problem occurs. For information about how to back up, restore, and edit the 
registry, click the following article number to view the article in the Microsoft Knowledge Base:

  Q256986 Description of the Microsoft Windows Registry

SYMPTOMS
========

When you enable an individual user to use the relay functionality, the relay
procedure fails, and the user receives the following error message:

  550 Relaying Is Prohibited

CAUSE
=====

This issue can occur when you enter the subnet mask as (or if the mask is set
to) 255.0.0.0, 255.255.0.0, 255.255.255.0 or 255.255.255.255. If you click the
Routing Restrictions button in Exchange Server Service Pack 2 (SP2) or later,
you must enter a subnet mask.

RESOLUTION
==========

WARNING: If you use Registry Editor incorrectly, you may cause serious problems
that may require you to reinstall your operating system. Microsoft cannot
guarantee that you can solve problems that result from using Registry Editor
incorrectly. Use Registry Editor at your own risk.

To resolve this issue, use either of the following methods:

- Method One:

  1. Open the Internet Mail Service properties, click the Routing tab, and then
     click Routing Restrictions.

  2. Click to select the "Hosts and clients with these IP addresses" check box.

  3. Click Add, and then enter the user's IP address (for example,
     123.123.123.123) in the IP address box.

  4. In the Mask box, set the subnet mask to 255.255.255.<x>, where
     <x> is the last octet of the user's IP address (for example,
     255.255.255.123), and then click OK.

  5. Use the Services tool in Control Panel to stop and restart the Internet
     Mail Service.

- Method Two:

  1. Open the Internet Mail Service properties, click the Routing tab, and then
     click Routing Restrictions.

  2. Click to select the "Hosts and clients with these IP addresses" check box.

  3. Click Add, type the user's IP address in the IP Address box, type any
     subnet mask in the Mask box, and then click OK.

  4. Use the Services tool in Control Panel to stop and restart the Internet
     Mail Service.

  5. Start Registry Editor (Regedt.32.exe).

  6. Locate and click the following registry key:

  HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\MSExchangeIMC\Parameters

  7. Double-click the RelayAllowList value, delete the subnet mask and
     semicolon, (leaving only the user's IP address), and then click OK.

NOTE: After you finish this procedure, if you open the Internet Mail Service
properties, click the Routing tab, and then click Routing Restrictions, the Mask
box is blank. To apply these changes, use the Services tool in Control Panel to
stop and restart the Internet Mail Service.

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

For additional information on routing restrictions with Exchange Server 5.5,
click the article number below to view the article in the Microsoft Knowledge
Base:

  Q196626 XFOR: Restricting Routing in the Internet Mail Service

Additional query words: access denied error 0x800CCC79 0x800CCC78

======================================================================
Keywords          : kberrmsg 
Technology        : kbExchangeSearch kbZNotKeyword2 kbExchange550SP2
Version           : :5.5 SP2
Issue type        : kbprb

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

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.