support for mTLS

[anju-geetha-bai-db]

Hi Team,
is it possible to add mTLS support?
we need encrypted connection between relay and smtpGateway and the relay should be authenticated based on client certificate.
I played around with the codebase , but unsuccessful .
The error is " tls: first record does not look like a TLS handshake."

[decke]

If you want to really put this into smtprelay you will need to extend getTLSConfig().

As an alternative you could use something like a proxy in front to handle mTLS
https://github.com/habibiefaried/mtls-tcp-proxy