Catch-all
A catch-all is a special setting within a domain name that ensures that e-mail addressed to e-mail addresses that are not explicitly created as aliases or mailboxes can still be delivered. The catch-all is a special type of forwarder that forwards these e-mails to one or more chosen e-mail addresses.
Configuring a catchall ensures that a company or organization can be reached through any conceivable alias within a domain name. This prevents email from being lost due to mistakes, misspellings and miscommunications. Or because an existing e-mail address has been cancelled. The downside of this is that the recipient behind the catch-all will also suffer more spam.
