Office 365 is a collection of Microsoft Office offerings and migrating from your local exchange server to the Office 365 hosted exchange email service requires coordinating a number of moving parts.   It is important to get it right or the company will have email downtime and people will get rejections when email your office.  We specialize in helping companies upgrade to Office 365. 

Hosted exchange standard mailbox size is 50 Gig, which is a healthy size mailbox.  If you are tired of email over quota messages and having to delete stuff all the time then consider Microsoft hosted exchange to be an almost unlimited email storage solution because you can also add online archiving on top of the base 50 Gig email box.