Require TLS Encryption

Once you've enabled TLS encryption on your virtual server, you must require it in all client and server connections.

To require TLS encryption:

1. Start System Manager
   On the Start menu, point to Programs, point to Microsoft Exchange, and then click System Manager.
2. Navigate to the SMTP virtual server.
   1. Servers
   2. Server
   3. Protocols
   4. SMTP
   5. SMTP virtual servers
   6. SMTP virtual server
3. Right-click the SMTP virtual server, and then click Properties.
4. On the Access tab, under Access control, click Authentication.
5. In Authentication, select Basic authentication.
6. Select the Require TLS encryption check box.
7. In Default domain, type the Windows domain which, by default, will be used to authenticate users.

   Note   Users outside the default domain will also be able to authenticate, provided an Active Directory trust relationship exists between their domain and the default domain. Users outside the default domain will have to specify the domain authorized to validate their credentials.

8. To return to the Access tab, click OK.
9. Under Secure communication, click Communication.
10. In Security, select the Require secure channel check box.