Since the Devuan 3 to 4 upgrade, my Exim 4.94.2 installation has a
problem with TLS certificates.
The local exit is set up to relay outgoing mail that is sent by
user X to server B and all other outgoing mail to server A. Both
servers require TLS for outgoing mail. But exit does not use TLS
for server B and generates this log message:
... TLS session: (certificate verification failed): certificate
invalid: delivering unencrypted to H=<server-b> [<ip-address>]
(not in hosts_require_tls)
