XADM: Text Attachments Appear Corrupted Because IMS Uses Quoted-Printable Encoding

ID: Q182307

The information in this article applies to:

Microsoft Exchange Server, versions 5.0, 5.5

IMPORTANT: This article contains information about editing the registry. Before you edit the registry, make sure you understand how to restore it if a problem occurs. For information on how to do this, view the "Restoring the Registry" online Help topic in Regedit.exe or the "Restoring a Registry Key" online Help topic in Regedt32.exe.

SYMPTOMS

Some messages with attachments sent by the Exchange Server Internet Mail Service may be encoded with Quoted-Printable encoding. If the message is received by an older MIME-compliant client, the attachment may be shown as corrupted text.

CAUSE

Exchange Server 4.0 uses Base64 encoding; Exchange Server 5.0 and 5.5 Internet Mail Service use Quoted-Printable encoding for text attachments. Because many older POP3 clients are still not Quoted-Printable aware, they may fail to decode the attachment properly.

RESOLUTION

To resolve this problem:

Install the provided hotfix and add the registry key shown below.

WARNING: Using Registry Editor incorrectly can cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that problems resulting from the incorrect use of Registry Editor can be solved. Use Registry Editor at your own risk.

For information about how to edit the registry, view the "Changing Keys And Values" Help topic in Registry Editor (Regedit.exe) or the "Add and Delete Information in the Registry" and "Edit Registry Data" Help topics in Regedt32.exe. Note that you should back up the registry before you edit it.

Start Registry Editor (Regedt32.exe or Regedit.exe as appropriate for your version of Windows NT).

Go to the following key in the registry:


      HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Service\MSExchangeIS
      \ParametersSystem\InternetContent

On the Edit menu, click Add Value and use the following entry:


      Value Name: ForceBase64
      Data Type:  REG_DWORD
      Value:      0x1

Exit Registry Editor.

STATUS

Microsoft has made this fix module for Microsoft Exchange Server, version 5.0.

A supported fix is now available, but has not been fully regression- tested and should be applied only to systems experiencing this specific problem. Unless you are severely impacted by this specific problem, Microsoft recommends that you wait for the next Service Pack that contains this fix. Contact Microsoft Technical Support for more information.

This fix has been posted to the following Internet location:

ftp://ftp.microsoft.com/bussys/exchange/exchange-public/fixes/Eng/Exchg5.0/Post-SP2-STORE/

Microsoft has confirmed this to be a problem in Microsoft Exchange Server version 5.5. This problem has been corrected in the latest U.S. Service Pack for Microsoft Exchange Server version 5.5. For information on obtaining the Service Pack, query on the following word in the Microsoft Knowledge Base (without the spaces):

S E R V P A C K

MORE INFORMATION

This fix allows you to add a new registry key so you can choose Base64 encoding. The new registry entry is called "ForceBase64."

Additional query words: IMS QP pop pdf adobe

Keywords : kbusage kbbug5.00 XADM kbbug5.50
Version : WinNT:5.0,5.5
Platform : winnt
Issue type : kbbug