Equisys technical notes

Technical guidance, explanations and fixes for our products

FIX: Unable to forward fax via email with 64-bit Outlook



ID: ZTN1975

This Zetafax technical note applies to:

  • Zetafax (all versions)
  • All 64-bit versions of Windows running a 64-bit version of Outlook


When attempting to forward a fax via email from the Zetafax client the following dialog appears:


32-bit MAPI implementation in the Zetafax client is not compatible with 64-bit Outlook.


A detection mechanism has been implemented to support both 64-bit Outlook and 32-bit Outlook.

In some rare circumstances our mechanism may fail to detect the bitness of Outlook on the current system. In this case the above symptom will still be present and it is necessary to force the Zetafax Client to use 64-bit Outlook process by performing the following steps:

  • Close the Zetafax Client if it is open.
  • Go to the following location in the registry: HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Equisys\Zetafax

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

  • Create a new DWORD (32-bit) value named ‘ClientUseSimpleMAPI’ and set the value to 1
  • Restart the Zetafax Client.

Note that setting the value of ‘ClientUseSimpleMAPI’ to 0 forces the client to use the regular MAPI implementation. If you are required to restore the default behaviour of the Zetafax client then the ‘ClientUseSimpleMAPI’ key should be deleted from the registry.

Note : To resolve the issue on the Server OS you need to follow one of the two available options-

1.     This will apply to all users:

ZFCLIENT.INI on individual client machine profiles, in the [SERVER] section,

 add the following line: 

Mail: MAPI 

(note this will need to be done for all users with the problem)


At the same time, add Mail: MAPI to the ZFCLIENT.INI in the Zetafax Server\System folder and the Zetafax Client install folder to allow any new installing users or user logins to get the setting straight away.

 2. Edit the registry on the server:

    a. Open the registry editor and go to the following key: HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Windows Messaging Subsystem

    b. Add a String Value 'MAPI' with value 1




Last updated: 2nd January 2017 (SB/MW)

Keywords: Outlook, forward, 64-bit, default mail client

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