Cannot start TLS: handshake failure in postfix

Issue Description

I enabled smtp_tls_connection_reuse in Postfix main.cf and saw “Cannot start TLS: handshake failure” for new emails being generated and mail flow stopped.

Cause

I later figured out based on the doc that smtp_tls_connection_reuse has dependency on tlsproxy process and that wasn’t enabled in master.cf

Fix

• Uncommented tlsproxy line in /etc/postfix/master.cf file.

• Restarted postfix service

systemctl restart postfix

• Now email flow started working.

Thanks you for reading !