Policy
Do not automatically sign replies
This policy setting allows you to specify whether replies will be automatically signed. If you enable this policy setting, the option to respond automatically to a signed message with a signed response will be overridden, and an unsigned response will be the default reply to a signed message. If you disable or do not configure this policy setting, a signed response will be the default reply to a signed message.
c5c3ebf8aa38L_DonotautomaticallysignrepliesRegistry
Copy registry mappings
HKCU\software\policies\microsoft\office\16.0\outlook\security\nosignonreply (enabled) = 1
HKCU\software\policies\microsoft\office\16.0\outlook\security\nosignonreply (disabled) = 0Policy notes
This policy setting allows you to specify whether replies will be automatically signed. If you enable this policy setting, the option to respond automatically to a signed message with a signed response will be overridden, and an unsigned response will be the default reply to a signed message. If you disable or do not configure this policy setting, a signed response will be the default reply to a signed message.