There are about 100,000 students in the campus, each will have about 5GB email quota + 1 GB storage (for college assignments they need to submit on the web, etc.). There are about 5000 employees, each will have 10GB email allowance plus 5 GB for storage (to store their spreadsheets, tests, presentation, e-books, etc.). There is the university website which will require an extra 1GB to habdle (for candidates and students' forms, viedos, pictures, maps, etc.). They also have some kind of archive, let's assume 3 years back which mean about 160,000 students. Sum up everything...