I'm coding up some HTML email templates — something that I do rarely enough that I always find myself re-googling to remind myself of the latest constraints and pitfalls. A couple of good resources for css support in different email clients and contexts are, of course, Campaign Monitor and Mailchimp, but their webmail sections always seem to talk about Outlook.com, not Microsoft's browser-based Office 365 mail offering.
Can anybody confirm (or refute) that — for the purposes of css support and rendering — Outlook.com and Office 365 are equivalent?