(This blog post was first published on the original RMS team blog in July 2011.)

When using the Active
Directory Rights Management Services Bulk Protection Tool (http://www.microsoft.com/download/en/details.aspx?displaylang=en&id=11122)
with Microsoft Outlook 2007 or 2010 Personal Store (.pst) files, you may
experience a file truncation problem if Microsoft Outlook is set to process files
asynchronously. To prevent this issue, you can configure Outlook to operate in
synchronous mode by editing the Windows Registry.

WARNINGS:

  • Using Registry Editor incorrectly can cause
    serious, system-wide problems that may require reinstallation of your operating
    system to correct them. Microsoft cannot guarantee that any problems resulting
    from the use of Registry Editor can be solved. Before editing the registry, be
    sure to back it up.
  • By switching Outlook from asynchronous to
    synchronous mode, message processing will likely become slower. 

For more information on registry
editing, see the following resources:

For more information about personal
storage folders, see How to
manage .pst files Outlook 2007, Outlook 2003, and in Outlook 2002 in Microsoft
Knowledge Base article 287070 (http://support.microsoft.com/kb/287070).

After backing up the registry, you must create the REG_DWORD
value SyncWMLoad and modify the entry to read 1. The following table shows the
paths and values for Outlook 2010 and 2007

Outlook version

Registry Path under: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft

Value Type

Value

To enable synchronous processing

To disable synchronous processing

2010

\Office\14.0\Outlook

REG_DWORD

SyncWMLoad

1

0

2007

\Office\12.0\Outlook

REG_DWORD

SyncWMLoad

1

0

The following figure illustrates the modification to enable
synchronous processing for an Outlook 2010 client computer: