XWEB: Using POST Command with Long URLs May Fail Due to 2-KB Limit in Exchfilt.dll

• Microsoft Exchange Active Server Components, version 5.0
• Microsoft Outlook Web Access, version 5.5
• Microsoft Outlook Web Access, version 5.5 Service Packs 1, 2

SUMMARY

When you use the POST command in an application with an URL over 2 KB in size (2048 characters), the POST command returns an error code instead of successfully posting.

MORE INFORMATION

The Microsoft Exchange Server Outlook Web Access (OWA) component installs a global ISAPI filter, Exchfilt.dll, which will not pass URLs over 2 KB in length. There is a fixed buffer size in Exchfilt.dll of 2048 characters.

If OWA is installed on your Microsoft Internet Information Server (IIS) computer, the ISAPI filter limitation on Exchfilt.dll may also affect other applications trying to pass a long URL.

For additional information on ISAP filters see the following article in the Microsoft Knowledge Base:

Q150312 How to Install an Isapi Filter DLL

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Windows NT 4.0 Options Pack online documents

Additional query words:

Keywords :
Version : WINDOWS:5.0,5.5
Platform : WINDOWS
Issue type : kbinfo