Go to your iPhone or iPad’s Settings
For iOS 14: Go To Settings > Mail > Accounts > Add Account
For iOS 12/13: Go To Settings > Passwords & Accounts > Add Account
For iOS 11: Go To Settings > Accounts & Passwords > Add Account
For iOS 10: Go to Settings > Mail > Account > Add Account
On the Add Account screen, tap Microsoft Exchange.
Enter the full email address in the Email field and your mailbox password in the Password field, then tap Next.
The device offers to immediately sync with the Exchange server. If you choose not to sync at this time, you can turn on calendar and contact syncing later in Settings > Accounts & Passwords > Account, tap on your account.
To complete the setup process, tap Save and wait for the iPhone to test your incoming and outgoing mail settings and connect to your mailbox.