Mutual-TLS between Exchange 2007 and external domains.
Couple of people have raised calls regarding this.
Surprisingly (well, not), the documentation from Microsoft is rather bizarrely.. well, Microsoftised.
However, it is decent background reading anyway, so I will paste here the required links (for Exchange 2007 mind), and possibly later post with a “shortened” version for normal people to understand.
Fantastic (eugh) reading, so get ready to be Microsoftised and enjoy it 😉