A lil bit more about MS's new strategic focus on security - this time MS replaces the integrated MTA in Exchange with a standalone one. Looks a lot like the classic embrace-extend-coopt play aimed at SMTP. The article talks a bit about how MS hopes it will become a 'security hub', because they've exposed an API for third-party plug-ins - that's nice, but quite obviously the real play is to grab control of messaging at the edge of the network itself.