Why I don’t use my Mobile Phone built-in Mail
We recommend user using “Outlook” apps, because apps is easy for update and fix the problem.
If you using iPhone/Andriod built-in “Mail” you should always update your phone to the latest version, if you got a problem on built-in “Mail”, you can’t get Microsoft support, we found many problems on Andriod and iPhone built-in “Mail” so please using Outlook Apps.
iPhone using Office 365 Calendar and Contact
On iPhone Setting > Mail, Contacts, Calendar > Add Account > Exchange
Remember select “Exchange” and just simple type username and password
Just disable the “Mail”
Please backup your mobile
Such as Calendar, Contacts, what you will
Enable on your phone. Because iCloud
The setting may be will ask you replace or
Combine the contact or calendar.
Once combined contact may be easy to separate, but the calendar will let you crazy.