Configure Simple MAPI message opening prompt

This policy setting allows you to specify what occurs when a program attempts to gain access to a recipient field, such as the "To" field, using Simple MAPI.

If you enable this policy setting, you can choose whether Outlook always allows access to the recipient field, always disallows access to the recipient field, or prompt users to specify whether to allow or disallow access to the recipient field.

If you disable or do not configure this policy setting, Outlook prompts users to specify whether to allow or disallow access to the Address Book.

Guard behavior:

0. Prompt User
   

   Registry Hive	HKEY_CURRENT_USER
   Registry Path	software\policies\microsoft\office\16.0\outlook\security
   Value Name	promptsimplemapiopenmessage
   Value Type	REG_DWORD
   Value	1

1. Automatically Approve
   

   Registry Hive	HKEY_CURRENT_USER
   Registry Path	software\policies\microsoft\office\16.0\outlook\security
   Value Name	promptsimplemapiopenmessage
   Value Type	REG_DWORD
   Value	2

2. Automatically Deny
   

   Registry Hive	HKEY_CURRENT_USER
   Registry Path	software\policies\microsoft\office\16.0\outlook\security
   Value Name	promptsimplemapiopenmessage
   Value Type	REG_DWORD
   Value	0