MTA-STS support for Mail In a Box

... by A. Schippers in Doofpot 2020-02-28

After using Mail in a Box for years now, I wanted to add support for MTA-STS. A protocol, mainly used by google for negotiating TLS support on mail

I decided to do the testing and created a fork and made a pull request.

I already got the first responses. Fingers crossed to get it in the main distribution.