After upgrading to 0.44 from a very old version (0.28), my web applications (running on a separate server) can no longer establish an SMTP connection to my MiaB server. It seems to be an issue around versions of TLS, or possibly specific ciphers missing on the client. My
mail.log shows the following:
The error line appears to be:
warning: TLS library problem: error:14209102:SSL routines:tls_early_post_process_client_hello:unsupported protocol:../ssl/statem/statem_srvr.c:1655:
My web server is fairly out of date, but it does appear to be running a version of
openssl that should support TLS1.2. The specific configuration is:
I would try upgrading OpenSSL and PHP on the client machine, but I don’t want to risk breaking my production server right now if possible. Is there a way I can temporarily modify MiaB to fallback to an older version of TLS and see if this fixes the problem?