Port 587 is not TLS on connect. If at all possible use port 465, which is.
(Postfix can almost certainly be configured to connect in plaintext and then issue a STARTTLS command, but this method of security is considered obsolete by RFC8314. An active attacker could interfere with the plaintext part of the handshake to make it appear that STARTTLS is not mutually supported.)
(Postfix can almost certainly be configured to connect in plaintext and then issue a STARTTLS command, but this method of security is considered obsolete by RFC8314. An active attacker could interfere with the plaintext part of the handshake to make it appear that STARTTLS is not mutually supported.)
Statistics: Posted by jojopi — Mon Apr 21, 2025 12:30 am