On Wed, Jul 16, 2014 at 03:51:41PM +0200, li...@rhsoft.net wrote: > "secure" means enforce encryption while "may" allows fallback to plain > anything above requires DANE - the archives are your friend > without dane there is no real verification possible at all
This is not correct. The levels are documented, please don't make stuff up. Links to all levels: http://www.postfix.org/TLS_README.html#client_tls_levels Link to secure level: http://www.postfix.org/TLS_README.html#client_tls_secure Limitations of TLS with SMTP: http://www.postfix.org/TLS_README.html#client_tls_limits -- Viktor.