Making an email alias means making an email address which shares the same mailbox with a completely different e-mail address for both the incoming and the outbound messages. For instance, you’re able to create an e-mail address email@example.com and it will be connected to its own mailbox. Next, you can make an alias firstname.lastname@example.org, that can make use of the mailbox of sales@ and won't use a mailbox of its own. If you look at your emails, you will notice emails sent to either one of the two addresses in one location, which can be more convenient in some circumstances since you will not have to log in and out of different mailboxes working with webmail or configure various addresses in an email app. This option is often used as a substitute for forwarding emails from a single e-mail address to another if numerous addresses are listed for contact on a website.