1. Go to Settings, select Mail
2. Then tap Add account...of type Other.
3. Then tap Add Mail Account
4. Enter your Name, OMNIconnect email address, password and description, then tap Next.
5. Select IMAP or POP* and fill in the rest of your access details, using mail.omni.net.au as the Host Name for both the incoming and outgoing mail servers and enter your username (your email address) and passwords for both too. 

6. Tap Save and your phone should now try to connect to the server. If your phone displays a message asking to connect without SSL, you can pick Yes to finish setting up your account.

7. At your list of accounts, tap on your newly created account.

8. You should now have visible 'OUTGOING MAIL SERVER' with the setting 'SMTP: mail.omni.net.au' - tap this

9. Now tap your primary mail server.  At the bottom of the display, you will see the server port.  If this is 25, it needs to be changed to 587.

10. Tap 'Done' and exit your settings.  You will be able to send emails via your i-Device.

*If you use POP3 at another location, such as your PC, then your mail will download to that PC, and may not be available on the iPhone. This will depend on the settings on your PC.