Can SMTP with TLS do root certificate authentication?

HCL Domino Domino Forum
1

Don’t know much about Authentication within TLS on Domino. My questions are:1. Why would I use a trusted CA for my SMTP - TLS servers instead of a self-cert?

  1. How can I confirm that my SMTP-TLS server does certificate authentication?

  2. What happens to mail if the incoming TLS session comes from a server that does not have a known trusted CA?

and finally,

  1. How can I tell that emails sent or received via TLS supported servers were actually done over a TLS session? I can’t seem to see anything specific in the SMTP headers of those messages.

Thanks for any info on the subject.