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Q264731: XADM: MAPI Tasks Don’t Work with Virus API Anti-Virus Software

Article: Q264731
Product(s): Microsoft Exchange
Version(s): 5.5 SP3,5.5 SP4
Operating System(s): 
Keyword(s): kberrmsg exc55sp3
Last Modified: 16-AUG-2002

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The information in this article applies to:

- Microsoft Exchange Server, versions 5.5 SP3, 5.5 SP4 
- Microsoft Exchange 2000 Server 
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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 attempt to perform Messaging Application Programming Interface (MAPI)
operations on an Exchange Server computer that is running an anti-virus software
that is based on anti-virus application programming interface (API), you may
receive a MAPI time-out error message.

These MAPI operations include the following:

- Performance of an offline folder synchronization (.ost synchronization).

  When an .ost synchronization does not work, if you view the .ost
  synchronization log it includes the following error message:

  

  12:51:31 Error synchronizing folder
  12:51:31 [80004005-501-0-550]
  12:51:31 The client operation failed.
  12:51:31 Microsoft Exchange Server Information Store

In addition, in Microsoft Outlook 2002, the following error message is displayed
during the synchronization:

  The Microsoft Exchange server reported error 0x00040820

- Performance of a Move Mailbox operation.

- Use of the Microsoft Exchange Mailbox Merge program (Exmerge).

- Export to a personal folder file (.pst file).

When you move messages from a mailbox to a .pst file, you may receive the
following error message:

  Some items could not be copied. They were either moved or deleted, or access
  was denied.

CAUSE
=====

This issue can occur if these MAPI operations gain access to a large number of
attachments that have not been scanned by using the current virus signatures.
The MAPI operations do not determine that the attachments are waiting to be
scanned; therefore a time-out error message is displayed if the scans are not
completed to make the attachments available to the MAPI request in a sufficient
amount of time.

NOTE: Any Microsoft Outlook user or any third-party package (for example a backup
package) that needs to access messages or attachments may encounter this problem
if the anti-virus software package uses VAPI 1.0.

WORKAROUND
==========

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 work around this issue, make sure that the BackgroundScanning value is enabled
and increase the OpenRetryDelay value from the default setting.

NOTE: These procedures reduce, but may not eliminate, the number of error
messages that are displayed during MAPI operations.

To enable the BackgroundScanning value, you need to edit the registry:

1. Start Registry Editor (Regedt32.exe).

2. Locate the BackgroundScanning value under the following key in the registry:

  HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MSExchangeIS\VirusScan

3. If the value is set to 0, change the value to 1; double-click the entry and
  change the value to 1 Binary.

4. Quit Registry Editor.

The BackgroundScanning process begins one minute after you change this key.

After you enable the BackgroundScanning value, Microsoft recommends that you
allow approximately one hour to pass for each gigabyte (GB) of attachments that
is stored in your private information store before you perform a MAPI operation,
to ensure that all attachments have been scanned. After that amount of time,
MAPI error messages are greatly reduced or may be eliminated.

To increase the OpenRetryDelay value:

1. Start Registry Editor (Regedt32.exe).

2. Locate the OpenRetryDelay value under the following key in the registry:

  HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MSExchangeIS\VirusScan

3. On the Edit menu, click DWORD, type "5000" (without the quotation marks), and
  then click OK (This is a decimal entry).

4. Quit Registry Editor.

If the OpenRetryDelay value does not exist, create it:

1. Start Registry Editor (Regedt32.exe).

2. Locate the following key in the registry:

  HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MSExchangeIS\VirusScan

3. On the Edit menu, click Add Value, and then add the following registry value:

  Value Name: OpenRetryDelay
  Data Type: REG_DWORD
  Radix: Decimal
  Value: 5000

4. Quit Registry Editor.

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

Attachments are scanned when they are sent or received by the Exchange Server
computer if the anti-virus API is enabled. However, those attachments that are
already present when you install the anti-virus software or update the virus
signature file need to be rescanned when an operation gains access to those
attachments, unless the BackgroundScanning process has scanned those
attachments. This ensures that those attachments have been checked with the
latest virus signature file. The BackgroundScanning process begins a full scan
of all attachments in the information store when virus signatures change or the
vendor of the virus software changes.

The BackgroundScanning process is disabled by default on many types of
third-party anti-virus software.

In addition, the OpenRetryDelay value that the anti-virus software uses
determines the time interval, in milliseconds, that the information store pauses
before the information store attempts to reopen attachments that are being
scanned when they are requested by the client. If the attachment is not scanned
and made available to the MAPI request within this time interval, a time-out
error message is displayed.

By default, the information store uses a setting of 500 milliseconds (msec), or
one-half of a second, unless otherwise specified in the registry.

All attachments are rescanned after virus signatures are updated. Before an
operation can gain access to these attachments, it is important that you plan a
signature update to occur during off-peak hours. This allows time for the
attachments to be scanned and made available to MAPI operations. Due to the way
that some anti-virus vendors update their product, stop and restart the
information store after a virus signature upgrade to re-initiate the background
scanning task.


Additional query words: VAPI 80004005-501-0-550 exch2kp2w ol2000 ol2k ol2002

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Keywords          : kberrmsg exc55sp3 
Technology        : kbExchangeSearch kbZNotKeyword2 kbExchange2000Search kbExchange2000Serv kbExchange550SP3 kbExchange550SP4
Version           : :5.5 SP3,5.5 SP4
Issue type        : kbprb

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