Are you devices already connected to receive email from Office365?
If so that's fine because it means you should be able to get access to email, calendar and contact info as well from mobile devices.
You will need to test this out before deploying the solution:
- Delete the account
- Create a new account using the ExchangeActiveSync.
- Do a manual configuration (not automatic)
- Specifie your user info in the fields:
~~ username = email address (e.g. firstname.lastname@example.org) ~~
~~ servername = m.outlook.com ~~
Hopefully, the device should configure the rest and in a few minutes be able to see your email, contacts and calendar.
**if the post above has answered the question, please mark the topic as solved.