How to solve Outlook opening Mail Following Eroor

You Can Try This Setting For Following Step

You can disable it via;

Tools-> Trust Center-> Add-ins.
Or uninstall it completely via Programs and Features in the Windows Control Panel.
After updating or reinstalling the add-in, resetting your extend.dat file may help too.
See Resetting Data Files.
if not Satisfied This Setting Try this Another Trick -find an delete the following file:

c:\documents and settings\username\local settings\application data\microsoft\outlook\extend.dat.[Note Only extend.dat File Delete]