This is a registry file (can't recall source) that is worth comparing with yours: Windows Registry

This is a registry file (can't recall source) that is worth comparing with yours: Windows Registry Editor Version 5.00

[HKEY_CLASSES_ROOT\.MAPIMail] @="CLSID\\{9E56BE60-C50F-11CF-9A2C-00A0C90A90CE}"

[HKEY_CLASSES_ROOT\.MAPIMail\PersistentHandler] @="{098f2470-bae0-11cd-b579-08002b30bfeb}"

Those entries exist in my registry, but I can't say whether that matters in your situation.