Adding an exchange account to iPhone

Talk to your IT department or corporate help desk.

A step by step guide to add email account on iPad and iPhone

This process is valid for all mails, AOL, Google, Yahoo, Outlook, Hotmail, Exchange etc etc

1. Keep your email id and password handy
2. Use this link to find out your Incoming and Outgoing server settings by entering your email address

https://support.apple.com/mail-settings-lookup

If it is not available in the link above contact your email client

The GIF is self explanatory.

iCloud Account IMAP and SMTP

It would be better if you can please post a screenshot, in order to understand the phenomenon better.

You may get better and prompt responses if you may kindly provide the iPhone Model that you have and the iOS version if it is known to you.