STARTTLS opportunistically or use plain SSL, depending on your needs.
Only versions 2.8.x and higher or GnuTLS have been tested.
+[FIXME: this statement needs clarifying, given that GnuTLS >= 2.6.6
+is the test used by configure.]
*** gnutls-log-level
Set `gnutls-log-level' higher than 0 to get debug output. 1 is for