Creating an email alias means setting up an e-mail which shares the same mailbox as a different e-mail address for both the incoming and the outgoing email messages. For instance, you can create an e-mail address firstname.lastname@example.org and it'll be linked to its own mailbox. Then, you can create an alias email@example.com, which can use the mailbox of sales@ and does not have a mailbox of its own. If you check your emails, you will see e-mail messages sent to either one of the two addresses in a single place, which may be more convenient in some instances since you will not need to sign in and out of different mailboxes using webmail or configure various addresses in an email app. This feature is frequently used as a replacement for forwarding e-mails from one e-mail address to a different one if numerous email addresses are mentioned for contact on a web site.