On Fri, Jun 23, 2017, Viktor Dukhovni wrote:
> Some MTAs (say Sendmail) don't downgrade to cleartext at all when
> the peer purports to support STARTTLS. Postfix gives the remote
Just FYI: in sendmail 8.16 it's an option:
To automatically handle TLS interoperability problems for outgoing
mail, sendmail can now immediately try a connection again
without STARTTLS after a TLS handshake failure.
This can be configured globally via the option
TLSFallbacktoClear or per session via the 'C' flag
of tls_clt_features.
