Can I set my email up so 2 (or more) accounts receive mail sent to 1 address ?
Yes. Create a forwarder from the account receiving the mail to the account that should also get the mail.
For example, if people are emailing firstname.lastname@example.org but you also want email@example.com to receive that mail, set up a forwarder from firstname.lastname@example.org to email@example.com, and both accounts will receive the email.
Tip: You can add as many forwarders as you want to get copies of the email sent to more accounts.