The terminology is a bit confusing, so let’s clarify. What you really have is just one mailbox, not many. It acts as a catch-all mailbox for all mail sent to any addresses under your domain. You just need to set up folders and sorting rules to keep things tidy.

So let’s say you bought cool.tech and you made a single mailbox like inbox@cool.tech. Nobody sends mail there specifically, but that’s where it all goes because it’s a catch-all address. All the other addresses mail is sent to were never explicitly created, but they can receive anyway.

Instead, you get mail to addresses like ScammyAppName@cool.tech and iJustWantedToDownloadThisOneFile@cool.tech, etc. Anything sent to those addresses gets sorted into two separate folders within the only mailbox you’ll ever need. If you want the same email to appear in two folders, you would need to make a copy of it.