SYMPTOMS

The following .NET error is produced in browser when accessing web mail:

HTTP Error 500.19 - Internal Server Error
The requested page cannot be accessed because the related configuration data for the page is invalid.

Detailed Error Information:

Module DynamicCompressionModule

Notification SendResponse

Handler PageHandlerFactory-ISAPI-2.0

Error Code 0x8007007e

Requested URL http://mewebmail.localhost:80/Mondo/lang/sys/login.aspx

Physical Path C:\Program Files (x86)\Mail Enable\bin\NETWebMail\Mondo\lang\sys\login.aspx

Logon Method Anonymous

Logon User Anonymous

CAUSE

When running MailEnable web mail on a SharePoint server, SharePoint will set global compression schemes (32-bit) which conflict with the MailEnable web mail interface.

RESOLUTION

1. Locate the meinstaller.exe ulility under the MailEnable "BIN" folder

2. Double click to open the meinstaller's options window.

3. Execute option 13.

4. When prompted by the installer select the Microsoft .NET Framework 2.0 64bit in the dropdown menu.

5. Once complete recycle the MailEnableAppPool. 

REFERENCES

http://forums.iis.net/t/1149768.aspx