The old Office365 Outlook Web Apps using Exchange Server 2010.
and the New Office365 Outlook Web Apps using Exchange Server 2013. The obvious changes, is the fluid design, and better organize with links in the upper right corner of the website. I will report back with the user features once I notice them.
By the way, the Office365 upgrade from Exchange Server 2010 to 2013 is random according to one of Microsoft technical support that I've talked to. So, customer B will be next or customer X, but will happen this year for all customers.
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