What is a catch-all email address?
Understand catchall domains, named aliases and the cost of accepting unlisted recipients.
A fallback for unlisted recipients
A catch-all receives mail sent to an address that has not been created on your domain. If hello@example.com exists it follows its explicit route; a typo such as helo@example.com can go to the catch-all fallback.
Catch-all versus aliases and forwarding
An alias is a named address you deliberately create. Catch-all matches other recipients on that domain. Forwarding controls whether a saved message is copied to another inbox. Multiple domains forwarding to one inbox is not catch-all.
Enable it deliberately
After activating a domain, open Addresses and routing and save the catch-all switch. It starts off. Original recipients remain visible. In SimplerEmail, catch-all messages reply from the domain’s enabled support@ address, not automatically from arbitrary recipient names.
Spam and shared allowance
Catch-all can attract random-address spam. Each saved incoming message uses allowance; forwarding and replies use more. Catch-all stops accepting new unlisted-recipient mail at the monthly limit; rejected mail is not saved. Turn it off when you only need named addresses.