Aliases can be created and deleted from the Alias Administration page.
An alias is a synonymous, extra email address, which delivers all incoming mail to your main account.
Once you have created an alias it will begin to receive email within 15 minutes.
You can use your email alias from the Compose window by selecting it in the From drop down menu.
In an email client you can usually set up alternative email identities using your alias addresses. Please refer to the documentation for your particular email client.