This article contains technical information regarding WinZip's usage of the MAPI protocol. For a less technical article regarding MAPI issues and possible solutions, please see Why aren't WinZip's e-mail features working for me?
The WinZip features that make use of the MAPI protocol are Zip and E-Mail, Zip and E-Mail Plus, and Send To
Mail Recipient. These features will only be available if WinZip can successfully load the defined MAPI file (often MAPI32.DLL). WinZip tries to load this file out of the directory returned by the standard Windows GetSystemDirectory API call.
When using one of these features, WinZip issues the simple MAPI API called MAPISendMail, specifying the name of the open archive or the name of the Zip file to be created as a parameter. WinZip has no control over the application that will respond to the MAPISendMail command. If you have not been successful with setting the default e-mail application (see the article in the link above), you may need to edit the registry settings responsible. To do this:
- Click Start
- In the field above Start (or in the Run dialog) type: regedit
- Press Enter on the keyboard
Note: Windows 7 and Windows Vista users may need to click Yes in a User Account Control dialog
- Browse to, expand, and click on the following key:
HKEY_LOCAL_MACHINE\SOFTWARE\Clients\Mail
- The Default value should be the name of the e-mail application you have configured as listed in one of the subkeys. If it is not, right click Default, choose Modify, and enter the correct value.

- Now check the Default value in HKEY_CURRENT_USER (HKEY_CURRENT_USER\SOFTWARE\Clients\Mail
- If this Default is not correct, modifiy it (see step 5)
When you have finished editing the registry, close the Registry Editor and test a MAPI function. If you continue to have difficulty, please e-mail Technical Support.