I was just configuring my Windows 8 Test-Installation on my Laptop for my e-mail account -the Standard Winmail App on the Surface. I noticed there is only a configuration option for legacy ssl and not tls – my account being setup as standard IMAP TLS and SMTP TLS, so I was wondering. Short googling revealed that just entering your server and login credentials without activation the „this server uses ssl“ hooks should result in Winmail using TLS if offered by the server.
„Lucky“ as I am hosting my e-mail and my webpages myself I can confirm this behaviour: My IMAP and SMTP services offer TLS and as I can see in the log files Winmail connects and starts the TLS session correctly and supplies the credentials after the encrypted connection is established.