To add your Exchange account to an iOS device:

1. Go to Settings > Passwords & Accounts, then tap Add Account.

2. Tap 'Microsoft Exchange'.

3. Put in your Email address and for Description, I would also put in your email address.

4. Tap 'Configure Manually'

5. Type in your Password, and tap 'Next'

6. Most of the time that is all you need to do. If another screen pops up, here are the settings:

Domain: exg7.exghost.local
Server: us.exg7.exghost.com