2022-11-21 21:10:42 TLS error on connection from r218.notifications.rbs.co.uk [130.248.154.218] (gnutls_handshake): A TLS fatal alert has been received.
However, I can't see how to get any more information. I've tried
setting
add_environment = GNUTLS_DEBUG_LEVEL=3
in the exim4 config file, but it doesn't appear to do anything.