An email alias is actually an email address that shares a mailbox with a different e-mail. For example, you could have firstname.lastname@example.org plus email@example.com and emails sent to either one of them will be received in one and the same mailbox. This feature will make it simpler and more convenient to control a variety of addresses since you will have to log into one single mailbox if you work with webmail as well as create one address in a email application on your computer. If you create an alias, not only will you be able to get messages, but you'll also be able to send out e-mails from the various addresses and they'll share the Outbox, so you'll have all communication in one place. Implementing aliases is an alternative to making use of different mailboxes for various purposes or forwarding one e mail address to another in order to control the communication of both in a single place.