A catchall address is a designated mailbox where any email sent to a non-existent email address will be delivered. To better help explain catchalls, review the example below:

You have the following mailboxes setup on your account:

[email protected]
[email protected] (Which is set as the catch-all)

Now in this example, any email sent to [email protected] would be delivered to that corresponding mailbox.

The same would hold true for any email sent to [email protected].

However, what would happen if an email was sent to “[email protected]”?

Because the mailbox [email protected] has not been setup in the system, normally the email would be rejected with a “user unknown” message and would be returned to the sender.

However, if you have a catchall setup, like in the example above, the email would be delivered to the catch-all mailbox which in this case is ‘[email protected]’

This would hold true for email sent to any other addresses which have not been setup as mailboxes on the system (ie [email protected])

We sometimes also refer to this email address as the Default Email.