I can only provide some insides with UK universities. There also students very frequently were using GMail and just used mail forwarding from their university

I can only provide some insides with UK universities. There also students very frequently were using GMail and just used mail forwarding from their university email accounts. With at least one large UK university we've seen very strong uptake of the MS Office apps & email (85% vs 30% in the years before). They also have a large number of distance learners for which these solutions are substantially better than what the university offered previously so that might skew the numbers a bit. Uptake of OneDrive for example was much lower around 40% 3 months after the roll-out but still rising. Stats that MS provides on this are mainly MS Exchange (online) based (plus some SharePoint / OneDrive data - the rest of the stats they provide are at best historic or unusable). At the same time when the university wanted to communicate with all students besides their course work, they used Twitter or Facebook and not email.