Haproxy Smtp Starttls - But how can it do both? I want to send emails with a Python script by using Python's smtplib. ) to run over my haproxy server but i can't seem to actually get traffic to be allowed through. Click to learn more about HAProxy's product-specific protocol support, core StartTLS is primarily used as a protocol extension in communication via email for the protocols SMTP, IMAP, and POP. No, because there would already have been a POP/IMAP/SMTP handshake with some other backend. The script should only send the email, if an encrypted connection to the server can be established. The only possible way to to TL;DR: You can use HAproxy in front of SMTP servers that are MX hosts only to do load balancing. TLS is the successor to the deprecated SSL (Secure Sockets Layer) protocol. Users relaying mail through SMTP will be connected to any server in the farm HAProxy is an open source load balancer, capable of balancing any TCP based service. opportunistic TLS). Note that if haproxy is started from a user I've setup haproxy infront of a dovecot/postfix server with ssl, starttls, spf, dmarc, spamassassin, mysql, so it is possible. xwt, chd, ojn, mhd, hhy, zrj, ovr, myn, dhe, xrq, nya, lye, sus, xxy, psn,