How to setup Exchange Online / Office 365 e-mail account to your iPhone's
1. Click "Setting" on your iPhone's
2. Click "Mail, Contacts, Calendars"
3. Click "Add Account"
4. Click "Exchange"
5. Enter your e-mail address, password and description.
Description is what name you want to display on Mailboxes list, check right side picture, such as "iCloud" & "MYS"
6. You can enable what function you need.
7. Check this picture, you will see "MYS" seperate on upper and down side, the difference is upper only show inbox and latest e-mail only, down side will connect to Exchange Online/Office 365 server and show all e-mail and folder.