Note: If Accounts is not visible, click on Passwords and Accounts instead of Mail
Select Add Account
Select Other from the menu
Select Add Mail Account
Enter your account information: Enter your Name, Email & Password > Next
Configure Incoming and Outgoing Servers:
Select IMAP (default) or POP according to your needs.
Scroll down to Incoming Mail Server and enter all the relevant details, then do the same for Outgoing Mail Server, as in the screen below and then select Next.
Host Name:
Incoming mail server: has mail. before the domain name e.g. mail.example.com*
Outgoing mail server: has smtp. before the domain name e.g. smtp.example.com*
Ensure that Username is the full email address
Username & Password are the same for both Incoming & Outgoing servers
Click Save
Congratulations! You have now successfully configured your email account on your iPhone.