To much differences between Mail Plus and Proton Unlimited: only 15Gb space for Mail Plus (to share between Mail, Drive and Calendar) it's not enough for the price of the service. And it's for me to expensive to upgrade to Proton Unlimited (that have 500Gb of space). I also have Microsoft 365 and for 69,00euro/year i have 1Tb of space (and all the Office 365 pack, of course). It would be NICE if You upgrade the MINIMUM space for Mail Plus to 50Gb (it will be a GREAT plan!).