1. Go to the Main Menu (The quickest way to do this is to press the Home button which is the only button on the front of the device or Swipe Up from the bottom of the screen when no button is present)

2. Select Settings which should look like the image below

3. Scroll down and tap on (menu selection changes with operating system version)

Accounts & Passwords (iOS11)

Passwords and Accounts (iOS12)

Passwords & Accounts (iOS13)

Mail (iOS14/15/16/17)

4. Select Accounts > Email Address > Email Address and revise with the details listed below

Incoming Mail Server 

• Host Name: mail.ddns.com.au
  
• Username: youremail@yourdomain.com.au (your complete email address)
• Password: Your email password

For Outgoing Mail Server, tap on SMTP
Then tap on the Primary Server and revise with the details listed below

• Server: On