InformatiQ

Microsoft Exchange Hosted Services is a new service by Microsoft to provide email security services, in short it scans incoming and outgoing mails for SPAM, Virus and policy violations.
what i discovered is that their smtp service is running POSTFIX

rhanna@rhanna:~$ dig somedomain.com MX

; <<>> DiG 9.3.2 <<>> npcegypt.com MX
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 13422
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 2, ADDITIONAL: 2

;; QUESTION SECTION:
;somedomain.com. IN MX