An email alias is actually an e-mail that shares a mailbox with a different e-mail. For example, you could have email@example.com plus firstname.lastname@example.org and emails sent to either one of them will be received in one mailbox. This feature will make it easier and much more convenient to handle multiple e-mail addresses since you will have to log in to one single mailbox if you use webmail as well as set up just one address in an email app on your desktop. When you create an alias, not only will you have the ability to get messages, but you will also be able to send out messages from the different addresses and they will share the Outbox, so you'll have all communication in one location. Working with aliases can be a replacement for working with different email addresses for several purposes or forwarding a single e-mail address to a new one to be able to handle the e-mails of both in a single location.