I asked this question:
This question is unique as it asks specifically about the contradictory email and how I should proceed with it or ignore it. I think this question has a lot of value since others may be facing this same issue, that is their logs show all clients are connecting with TLS 1.2 but Salesforce is sending email to the contrary.
It is clearly (to me at least) not a duplicate of this question, which others have marked it as:
This question asks how I can be sure that a .Net app is calling the site via TLS 1.2. What more can I say in my question to show it is not a duplicate?