The Catch-All (Default) Address and Why We Set It to Fail Print

What the default address is

Every domain has a default address setting, also called the catch-all, and it decides what happens to mail sent to an address on your domain that does not exist. Someone emails sales@yourbusiness.tld, but you never created a sales@ mailbox or forwarder, what should the server do with that message? The default address setting is the answer to that question.

There are two sensible answers, and understanding the difference matters more than it first appears.

The two options

• Fail (reject the mail). The server refuses the message and tells the sender it could not be delivered, because no such address exists. The sender gets a clear bounce, and knows their mail did not get through.
• Catch-all (send it to a mailbox). The server accepts the mail anyway and drops it into a nominated mailbox, so nothing addressed to your domain is ever refused, whatever address it was sent to.

Catching everything sounds appealing, and it is the wrong choice for almost everyone. Here is why.

Why we preconfigure the default to Fail

On our servers, the default address is set to fail, deliberately, and it is the setting we recommend you keep. The reason is spam.

Spammers routinely send mail to invented addresses at real domains, sequences of guessed and random names, hoping something lands. If your domain is set to catch-all, every one of those invented addresses is accepted and dumped into your catch-all mailbox, which fills rapidly with junk aimed at addresses that never existed. A catch-all mailbox on a domain of any age becomes a spam magnet, and it wastes your storage on mail that was never really for you.

Setting the default to fail stops this at the door. Mail to a real address, a mailbox or forwarder you created, is delivered normally. Mail to an address that does not exist is cleanly refused, and the spammers guessing at random addresses get nothing. Your legitimate mail is entirely unaffected, because legitimate mail goes to addresses that actually exist.

"But what if I miss a message?"

The worry people have is that fail means missing mail sent to a slightly wrong address, a typo, someone guessing info@ when your address is hello@. In practice, fail handles this better than catch-all, because when the server rejects the message, the sender receives a bounce telling them it did not get through. A real person who mistyped your address finds out immediately and can correct it. With catch-all, that same message vanishes silently into a flooded junk mailbox nobody reads, so the mail is far more likely to be genuinely lost. Fail tells the sender; catch-all buries the message. Fail is the safer choice for not missing mail, not the riskier one.

The right way to make sure mail is received

If you want to receive mail at a particular address, the answer is not a catch-all, it is simply to create that address, as a mailbox or a forwarder, covered in our articles on managing email accounts and setting up forwarders. Create the addresses you actually use, forward the role addresses you want into your main inbox, and let the default fail for everything else. That gives you every message meant for you, cleanly, without the spam.

If you think you genuinely need a catch-all

There are rare cases, an unusual workflow that legitimately receives mail at many varying addresses. If you believe yours is one, talk to us first rather than simply switching it on, so we can look at what you are actually trying to achieve. Often there is a tidier way to get the result without turning your domain into a spam collector, and if a catch-all really is the right tool for your case, we will help you set it up with your eyes open to the trade-off.

Good to know

The fail setting is one of those quiet defaults that protects you without you ever noticing, which is exactly why it is worth understanding rather than changing on a hunch. It keeps your domain clean, refuses spam aimed at invented addresses, and, counterintuitively, makes you less likely to lose a genuine message, because real senders get told when they have the wrong address. Leave it on fail, create the addresses you actually want, and your email stays both complete and clean.