How to set up Office 365 Exchange Online email for Windows Phone 10 devices
This how-to only applies for users who are already migrated to Office 365 Exchange Online (Cloud system).
1. Go to "Settings" then tap "Accounts".
2. Choose "Your email and accounts".
3. Choose "Add a work or school account".
4. Enter your email address as a username and your RMA domain password as a password. Then tap "Sign in".
5. Once done, tap "Add an email account" and choose your account you just added.
6. When done, your account will be shown under "Email, calendar, and contacts".
If you require further assistance, please open a support ticket.