How do I use a catch-all address and aliases on my own domain?

What is the difference between an alias and a catch-all?

An alias is an address you create by name, and a catch-all is a rule that accepts every name you did not create. Both land in a mailbox you already have. If you create the alias [email protected], only mail to that exact name arrives. If you switch on the catch-all, mail to [email protected] arrives, including names you never thought of.

The two work together. The mailbox keeps a short list of named aliases, and the catch-all picks up the rest. At Fastmail a specific alias wins over the catch-all, so a named address is never swallowed by the wildcard.

This is only possible because the domain is yours. An address at a provider's own domain, such as @proton.me, @tuta.com or @mailbox.org, belongs to that provider: if you leave, you lose it. An address at your own domain moves with you, which is the point of a custom email domain.

Which providers support a catch-all on a custom domain?

Four providers document a catch-all in the help pages Postelva read: Proton Mail, Tuta, Mailbox.org and Fastmail. Zoho Mail, Migadu, iCloud+ and the other providers in the index may offer a similar feature, but the pages read on 12 November 2026 did not say so, and Postelva does not state it as a fact.

According to Postelva's index of 12 November 2026, 4 of the 14 providers checked document a catch-all for custom domains, and all 4 limit it to paid plans. Nothing at a provider changes your domain: the domain is registered at Postelva, and the provider only receives the mail that your MX records send to it.

How do I set up a catch-all at each provider?

The steps differ, but every provider asks for the domain to be verified and its MX records to be live first. Finish the provider setup before you switch the catch-all on.

Does plus addressing work on a custom domain?

Plus addressing sends [email protected] to the inbox of [email protected], and support depends on the provider. Proton Mail supports it with no setup. Fastmail supports plus addressing and also subdomain addressing. Tuta's support states that it does not support plus addressing on Tuta-owned domains. For a custom domain, no official page read on 12 November 2026 confirmed the behaviour at Proton or Tuta, so test it with one message before you rely on it.

A catch-all gives the same result with a stronger property: a site cannot guess your real address by deleting the part after the plus sign, because the whole name is different.

Is a catch-all a good idea?

A catch-all is useful for identifying who leaks your address and risky because it also receives guessed names. The privacy argument is simple: one address per website means a spam source can be traced, and one breached address does not expose the other accounts. Fastmail published this argument as a way to see which companies sell your data.

The cost is spam. Bots try common names at every domain, and the catch-all accepts them. A workable rule is to use the catch-all for registrations and newsletters, give real contacts a named alias, and switch the catch-all off or block it if the volume grows. The routing of every message still depends on the MX records, so if mail for a name does not arrive, read why email is not arriving at a custom domain.

Can I forward a name without a mailbox?

Yes: Postelva offers free email forwarding and URL forwarding from the client area. Forwarding relays one name to an address you already read, which suits a domain that has no mailbox. Choose one route for each domain: the MX records decide where mail for the domain is delivered, so a domain that points its MX records at Proton Mail, Tuta or Mailbox.org uses the aliases of that provider instead.

In short, Postelva is the place where you buy the domain and keep its DNS, and the mailbox provider is the place where the aliases live. Both pieces stay under your control.