An e-mail alias is an e-mail that shares a mailbox with a different e-mail. For instance, you could have firstname.lastname@example.org as well as email@example.com and messages sent to both of them will be received in just one mailbox. This option will make it a lot easier and much more convenient to control numerous email addresses since you will need to log in one single mailbox if you work with webmail as well as set up only one address in a e-mail client on your computer. When you set up an alias, you will not only be able to receive messages, but you will also be able to send out e-mails from the different addresses and they will share the Outbox, so you'll have all communication in a single place. Implementing aliases is surely an alternative to making use of different e-mail addresses for different purposes or forwarding one e-mail address to another one so that you can control the communication of both in a single location.