XFOR: MTA Includes Else Doorways into Previous Route Siblings (221699)

SYMPTOMS

The Microsoft Exchange Server Message Transfer Agent (MTA) can incorrectly route a message in an enterprise in which a large number of address spaces are used and several "else" branches exist.

CAUSE

The MTA will attempt to provide "else" doorway refinements in order to ensure that all possible routes are included in the GWART. If enough refinements exist, some "else" doorways may be unnecessary and cause a generic match to be found before all exact matches have been checked.

For example, if you have several available routes with multiple C=, A=, P=, and O= values in the GWART for routes to many connectors. One route might be set to indicate a generic route. That route should be added at the end under an "else" statement indicating that if all previous possible routes do not match, use this route by default. In this case (under certain circumstances), the route used under the "else" could also appear under previous values in the GWART.

RESOLUTION

To resolve this problem, obtain the latest service pack for Exchange Server version 5.5. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

191014 XGEN: How to Obtain the latest Exchange Server 5.5 Service Pack

The English version of this fix should have the following file attributes or later:

Component: Message Transfer Agent (MTA)

File name	Version
Dbserver.sch	N/A
Dcprods.cat	N/A
Ems_rid.dll	5.5.2562.0
Emsmta.exe	5.5.2562.0
Info4log.cfg	N/A
Infoblog.cfg	N/A
Infodlog.cfg	N/A
Infollog.cfg	N/A
Infotlog.cfg	N/A
Mtacheck.exe	5.5.2562.0
Mtamsg.dll	5.5.2562.0
P2.xv2	N/A
X400om.dll	5.5.2562.0
X400omv1.dll	5.5.2562.0

The fix can be applied to Exchange Server computers with Service Pack 2 installed.

STATUS

Microsoft has confirmed that this is a problem in Microsoft Exchange Server version 5.5 Service Pack 2. This problem was first corrected in Exchange Server 5.5 Service Pack 3.