Go to settings on the iPhone or iPad

Choose Apps

Choose Mail

Choose Mail Accounts

Choose Add Account

Choose Exchange

Enter your email address, a description for the account and choose Next.

On the pop up box choose Sign In

You may also get the following conformation screen, click continue

Would will be asked to Authenticate with Microsoft. Enter your password and click next

You may see the following popup. Click Accept

Choose which options you require and click Save