What is an email alias and how can I log into my eXp email?
Anemail aliasis simply a forwardingemail address. The mail server simply forwardsemail messagesaddressed to an email alias on to another, the specified email address.
So in your case...when email is sent to firstname.lastname@example.org it automatically forwards to your personal email address. Because this is an alias there is no login information needed because there is nothing to log into, other than your personal email address.
If you would like to send emails from your eXp Account please check out instructions for that here: Send As Instructions