Set up Exchange-based email accounts
When asked for a server name please use the following: outlook.office365.com
Scroll down for built-in Mail app.
Set up your email account using the Outlook for iOS app available from the Apple Store.
2. Enter your name, email address, password, and a description for your account.
Your iOS device will try to find your Exchange Server. You might have to enter additional server information. You might see a custom authentication page specific for your company.
If you're prompted to enter server settings, enter the following and tap Next.
When finished click Done.
The Mail app may request certain permissions. To agree, tap Yes.
Then choose the apps you want your email account to sync with your iOS device and tap Save.