You can create a mailing list that includes any number of the mailboxes created in your domain. An email sent from the mailing list will be delivered to each of these mailboxes.
To create a mailing list:
To go to the mailing list management page, click on its name in the list (on the right).
The number of mailing lists (as well as the number of domain mailboxes) is unlimited. By default, up to 1000 email addresses can be created in one domain. Information on how to create more mail addresses is provided on the corresponding Help page.