You won't find it in on line help.
Log in to https://www.optus.com.au/my-account
.Click on username and select Member Services
..Select My Internet Account
Log in again
Go to the User Management box
.Click on Add usernames
Hey @ReallyMODEDoff, you do not need to go into Member services to add your secondary email account. This can be done directly in My Account just follow these steps: Login into your My Account > On the dashboard - scroll down > click on your username to expand > Click on Settings (right hand side) > Click Manage next to Optus email account > Add email account > Fill out page (full name, username, password) > press ok. If you run into more trouble then chat with our Tech Support team to assist you further.