Good morning, we are testing Windows Mail App as a possible client to Exchange 2016 server from Internet. Our policy required username + password and client certificate. When I have a computer outside the domain I succesfully configure email account and in the account settings I can see the checkbox for automatically selection of user certificate. When I need, I can change the certificate for authentication. Everything works fine. But if is the computer in domain, I don't see the checkbox for selection of the certificate. Could you help me? Thanks for your advice. Jaroslav Vacek Czech republic