On Fri, Jan 31, 2014 at 12:54:01AM +0100, Johannes Bauer wrote: > What I would like to do and cannot figure out: How can I *force* > authenticated clients to perform a STARTTLS before performing a "AUTH > PLAIN"?
If plaintext mechanisms are all you have: smtpd_tls_auth_only = yes This disables auth completely without TLS. It looks like you have no other mechanisms available. -- Viktor.