Microsoft KB Archive/940348

= Error message for some hosted domains if you use the SMTP Event Sink (Smtpdomx.dll) in Hosting Messaging and Collaboration Solution (HMC) 3.5: &quot;Unable to relay&quot; =

Article ID: 940348

Article Last Modified on 11/15/2007

-

APPLIES TO


 * Microsoft Solution for Hosted Messaging and Collaboration 3.5

-



SYMPTOMS
In Hosting Messaging and Collaboration Solution (HMC) 3.5, there is a Simple Mail Transfer Protocol (SMTP) Event Sink (Smtpdomx.dll) to handle large number of SMTP domains. This sink is installed on all front-end servers that are running Microsoft Exchange Server to handle incoming SMTP traffic. Sometimes, you receive the following error 550 message if you have lots of hosted domains:

Unable to relay

Usually, this message only happens for the most recently added domains.



CAUSE
This problem occurs because the Event Sink does not add an exclusive write-lock on the Domains.dat file when the Event Sink reads the Domains.dat file. In this case, the Event Sink does not finish reading the Domains.dat file because HMC 3.5 is updating that file to the new Domains.dat file version. And, HMC 3.5 only checks the Domains.dat file before the Event Sink accesses the Domains.dat file. Therefore, the Event Sink only reads a partial number of the domains from the Domains.dat file. Then, you receive an error 550 message if the Event Sink cannot handle an SMTP domain.



Hotfix information
A supported hotfix is now available from Microsoft. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing this specific problem. This hotfix might receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next service pack that contains this hotfix.

To resolve this problem, submit a request to Microsoft Online Customer Services to obtain the hotfix. To submit an online request to obtain the hotfix, visit the following Microsoft Web site:

http://go.microsoft.com/?linkid=6294451

Note If additional issues occur or any troubleshooting is required, you might have to create a separate service request. The usual support costs will apply to additional support questions and issues that do not qualify for this specific hotfix. To create a separate service request, visit the following Microsoft Web site:

http://support.microsoft.com/contactus/?ws=support

Prerequisites
To apply this hotfix, you must have Hosted Messaging and Collaboration 3.5 installed on the computer.

Restart requirement
You must restart Internet Information Services (IIS) on the computer after you apply this hotfix.

Hotfix replacement information
This hotfix does not replace any other hotfixes.

File information
The English version of this hotfix has the file attributes (or later file attributes) that are listed in the following table. The dates and times for these files are listed in Coordinated Universal Time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time item in Control Panel.



STATUS
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the &quot;Applies to&quot; section.

Keywords: kbhotfixserver kbfix kbexpertiseinter kbqfe KB940348

-

[mailto:TECHNET@MICROSOFT.COM Send feedback to Microsoft]

© Microsoft Corporation. All rights reserved.