Message Formats

This policy setting controls which message encryption formats Outlook can use. Outlook supports three formats for encrypting and signing messages: S/MIME, Exchange, and Fortezza.

If you enable this policy setting, you can specify whether Outlook can use S/MIME (the default), Exchange, or Fortezza encryption, or any combination of any of these options. Users will not be able to change this configuration.

If you disable or do not configure this policy setting, Outlook only uses S/MIME to encrypt and sign messages. If you disable this policy setting, users will not be able to change this configuration.

Support the following message formats:

0. S/MIME
   

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

1. Exchange
   

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

2. Fortezza
   

   Registry Hive	HKEY_CURRENT_USER
   Registry Path	software\policies\microsoft\office\16.0\outlook\security
   Value Name	msgformats
   Value Type	REG_DWORD
   Value	20

3. S/MIME and Exchange
   

   Registry Hive	HKEY_CURRENT_USER
   Registry Path	software\policies\microsoft\office\16.0\outlook\security
   Value Name	msgformats
   Value Type	REG_DWORD
   Value	3

4. S/MIME and Fortezza
   

   Registry Hive	HKEY_CURRENT_USER
   Registry Path	software\policies\microsoft\office\16.0\outlook\security
   Value Name	msgformats
   Value Type	REG_DWORD
   Value	21

5. Exchange and Fortezza
   

   Registry Hive	HKEY_CURRENT_USER
   Registry Path	software\policies\microsoft\office\16.0\outlook\security
   Value Name	msgformats
   Value Type	REG_DWORD
   Value	22

6. S/MIME, Exchange, and Fortezza
   

   Registry Hive	HKEY_CURRENT_USER
   Registry Path	software\policies\microsoft\office\16.0\outlook\security
   Value Name	msgformats
   Value Type	REG_DWORD
   Value	23