An email alias is an email address which uses the same mailbox along with the initial e-mail address. For instance, you can have [email protected] as the authentic e-mail address and create an alias [email protected] The 2 email addresses can share exactly the same mailbox, so e-mails sent to either one of them shall be received in one place. You can use aliases for various needs, like emailing various types of people or signing up on websites. If you ever start getting a number of spam, for instance, you can easily eliminate the alias while your original mailbox will not be impacted in any way and you'll keep the emails that you need. Aliases in many cases are perceived as an alternative to forwarding emails from one email address to another one if you are using a couple of addresses for contact on your website.