Note: This is relevant for people who have CPanel Email with Buzzword.
If you use G Suite (Google Apps) or Office 365 Exchange this does not pertain to you.
Fill in your username and password.
The username is the entire email address.
Choose the default program to use. (I like the middle one)
Welcome to your mail account. You can do all of the usual functions of emailing from here and the beauty is that it is always accessible as long as you have an internet connection.