Catch-all email domains are one of the most challenging cases in email verification.

While many tools stop at identifying a domain as catch-all, Anymail Finder goes further to determine whether a specific email address is likely to exist.

What is a catch-all domain?

A catch-all domain is configured to accept emails sent to any address, even if the mailbox doesn’t actually exist.

Example:

If a domain is catch-all:

• john@company.com → accepted
• john123@company.com → accepted

Even though only one (or neither) inbox may really exist, the mail server accepts both.

Why catch-all domains confuse most verifiers

Most email verification tools rely mainly on SMTP checks.

With a catch-all domain:

• The mail server responds “OK” to every email
• Tools can’t tell real inboxes from fake ones
• Emails are often labeled as catch-all, risky, or unknown

This makes it hard to know which emails are actually safe to use.

How Anymail Finder verifies catch-all emails

When Anymail Finder detects a catch-all domain, it runs additional checks beyond standard SMTP verification.

These checks help us distinguish emails that likely exist from emails that only appear valid because the domain is catch-all.

As a result, Anymail Finder can confidently return VALID results for many catch-all domains, instead of marking all emails as risky by default.

Clear example: how this works in practice

Let’s say you verify two emails on the same domain:

• apizzini@anymailfinder.com → VALID
• apizzini2@anymailfinder.com → RISKY

What this tells you:

• The domain is catch-all
• The first address shows strong signals of existing
• The second address does not

Most verification tools would label both as catch-all or risky. Anymail Finder identifies which address shows real deliverability signals.

What should I do with catch-all results?

• VALID → safe to use in your main campaigns
• RISKY → use with caution, preferably low volume or secondary sending

When an email can’t be confirmed with confidence, we always surface that risk so you stay in control.

Need help?

If you have questions about catch-all emails or verification results, feel free to reach out to our support team.

We’re here to help 😊

Updated on: 08/01/2026