Unable to connect from macOS mail client

Sun Feb 13 09:26:47 UTC 2022

When trying to add mail account to the macOS mail client, I get following error

Feb 13 13:05:15 imap-login: Info: Disconnected: Connection closed: SSL_accept() failed: error:14094416:SSL routines:ssl3_read_bytes:sslv3 alert certificate unknown: SSL alert number 46 (no auth attempts in 0 secs): user=<>, rip=157.48.200.20, lip=192.168.1.101, TLS handshaking: SSL_accept() failed: error:14094416:SSL routines:ssl3_read_bytes:sslv3 alert certificate unknown: SSL alert number 46, session=<5mZDV+HXxK+dMMgU>

How to fix it?

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Necktwi