ntbtls support is now available in master and we will release a TLS enabled
2.1.19 installer for Windows.
Right now it is somewhat limited and does not work with some sites, notably
those which allow only ECC ciphersuites. An example for such a site is
posteo.de. Note that posteo.net sends a a bogus certifcate with rediretion to
posteo.de.
Most other sites work.