SSL error connecting mail server from client
I have 3 domains on my cloudron and use it as a mail server for the 3 of them. I use 2 clients (fastmail and mailbird) to connect to it but yesterday out of nowhere I started getting a connection error on my clients.
Here is the error I get in fastmail: Hmm, that didn’t work. Could not connect to server: SSL error SSL connect attempt failed error:1416F086:SSL routines:tls_process_server_certificate:certificate verify failed
Similar error I get on mailbird. I can access my email and looks to be working ok on Roundcube, but can't access it on the other clients.
I checked some other posts but nothing worked so far. My cloudron is on AWS and already tried opening outbound 53 UDP and renewing certs, logs show no errors and certs appear to be valid.