Hello, It seems that a recent update to MariaDB has caused Postfix not to be able to connect to MariaDB, and a TLS version incompatibility message results in the Postfix mail log (I don't have the message in front of me at the moment, but I will update the post with it shortly). I have not researched the specific nature of the change in MariaDB yet, but I suspect that the minimum required TLS version was increase to v1.3 or similar. Has anybody else encountered this problem? I'm running ISPConfig on a vanilla Ubuntu 20.04 LTS machine. The MariaDB version is as follows: Code: $ mysql --version mysql Ver 15.1 Distrib 10.3.34-MariaDB, for debian-linux-gnu (x86_64) using readline 5.2 And the Postfix version as follows: Code: $ postconf mail_version mail_version = 3.4.13 The MariaDB and Postfix instances are both on the same server, so I was able to "quick-fix" this by forcing Postfix to connect over a local socket instead of a TCP connection. To do this, I simply changed the database host value in all of the relevant Postfix configuration files, e.g.: Code: sed -i 's/hosts = 127\.0\.0\.1/hosts = localhost/g' /etc/postfix/*.cf But this doesn't feel like a permanent fix (does ISPConfig ever overwrite these configuration files?), and it doesn't help anybody whose MySQL/MariaDB server is on a different host. Is the "proper fix" to upgrade Postfix to a newer version?