An email alias is an email which uses the same mailbox along with the initial e-mail. For example, you could have firstname.lastname@example.org as your authentic email address and create an alias email@example.com. The 2 email addresses will be able to share exactly the same mailbox, so e-mails sent to either one of them will be received in a single place. You can use aliases for several purposes, like communicating with various groups of people or registering on websites. Any time you start getting a great deal of spam, for example, you can just get rid of the alias whilst your original mailbox won't be impacted in the slightest and you will maintain the emails you need. Aliases are often viewed as a substitute for forwarding emails from one mailbox to another one if you work with more than one addresses for contact on your site.