Microsoft isn't the only one..they all do it

http://www.macrumors.com/2014/03/21/apple-email-terms/

Quote:
Apple, Yahoo, and Google all have terms of service that allow them to read users' emails if necessary, according to research done by The Guardian. Apple's iCloud Terms and Conditions includes a clause that gives Apple permission to disclose Account information and Content, including iCloud email, when necessary by law, to address security, fraud, or technical issues, or to protect the rights and property of Apple.
You acknowledge and agree that Apple may, without liability to you, access, use, preserve and/or disclose your Account information and Content to law enforcement authorities, government officials, and/or a third party, as Apple believes is reasonably necessary or appropriate, if legally required to do so or if we have a good faith belief that such access, use, disclosure, or preservation is reasonably necessary to: (a) comply with legal process or request; (b) enforce this Agreement, including investigation of any potential violation thereof; (c) detect, prevent or otherwise address security, fraud or technical issues; or (d) protect the rights, property or safety of Apple, its users, a third party, or the public as required or permitted by law.