XFOR: Cannot Specify Domains to Relay to in Internet Mail Service When Message Routing is Allowed

ID: Q195969

The information in this article applies to:

SYMPTOMS

When the Exchange Server Internet Mail Service is configured to allow message routing (relaying), there is no way to specify what domains are allowed or not allowed to be relayed to.


RESOLUTION

New functionality has been added to the Exchange Server Internet Mail Service to allow you to override any previous relay restrictions and specify that mail destined for a certain domain be relayed.

To obtain this feature, obtain the latest service pack for Exchange Server version 5.5. For more information, please see the following article in the Microsoft Knowledge Base:

Q191014 XGEN: How to Obtain the Latest Exchange Server 5.5 Service Pack

The English version of this feature should have the following file attributes or later:
Component: Internet Mail Service 

   File Name      Version
   -------------------------
   Imcadmin.dll   5.5.2424.0
   Msexcimc.exe   5.5.2424.0
This feature was first included in Exchange Server 5.5 Service Pack 2.


MORE INFORMATION

Installation

The Imcadmin.dll file requires a special installation process. This file must be copied to the Exchsrvr\Add-ins\Smtp\I386 directory and you must also perform the following steps:

WARNING: Using the raw mode of the Exchange Server Administrator program (admin /r) incorrectly can cause serious problems that may require you to reinstall Microsoft Windows NT Server and/or Microsoft Exchange Server. Microsoft cannot guarantee that problems resulting from the incorrect use of raw mode can be solved. Use raw mode at you own risk.

  1. Start the Microsoft Exchange Server Administrator program in raw mode by typing the following at an MS-DOS command-line prompt:
    admin /r


  2. Click Site, click Configuration, click the Add-Ins container, and select the Internet Mail Service for <platform>.


  3. On the File menu, click Raw Properties, and select File-Version from the Object attributes list.


  4. Click Editor, and then double-click File version.


  5. Type the proper version as shown above, and then click OK.


  6. Click Set to save the changes, and then click OK.


To implement this feature, perform the following steps:

  1. In the left pane of the Administrator window, click the Connections object under the appropriate site. In the right pane, click the Internet Mail Service, and then click Properties on the File menu. Note that the Connections object appears under the Configuration object.


  2. Click the Routing tab, and then click >Add< to add a domain to which you want to allow routing.


  3. In the Edit Routing Table Entry dialog box, type the domain to which you want to allow routing in the "E-Mail Sent to This Domain" box, select the radio button next to 'Override Relay Restrictions. Always "relay"', and then click OK.


  4. Click >Routing Restrictions<. If you have not already specified restrictions in the Routing Restrictions dialog box, click the "Hosts and clients with these IP addresses" check box to select it.

    *NOTE: Step 4. is important because without specifing any restrictions, any host or client and relay mail anywhere.


  5. Click >OK<, and then click >OK< again.


  6. Restart you Microsoft Exchange Internet Mail Service.


Example scenario:

Your domain is A.COM but you are responsible for relaying messages to B.COM and C.COM. You want to allow rerouting to B.COM and C.COM but not allow mail destined for any other domains to relay.

To do this, use step 2-3 in the implementation section above to create an entry for both B.COM and C.COM.

When a host sends a RCPT TO: destined for A.COM, B.COM, and C.COM, the mail will now be accepted. But, if a message is TO: any other domain, the host will get a "550 Relaying is Prohibited" and the Internet Mail Service will not accept the message for delivery. 


Keywords          : exc55sp2fea 
Version           : WinNT:5.5
Platform          : winnt 
Issue type        : kbinfo

Last Reviewed: April 14, 1999