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

What are catch-all domains - and why are they tricky?

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

For example:

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

Because the mail server accepts any address, basic SMTP checks alone can't distinguish real inboxes from fake ones.

This is why many verification tools label emails on these domains as catch-all, risky, or unknown.

How does Anymail Finder verify emails on catch-all domains?

When Anymail Finder detects a catch-all domain, it applies additional verification signals beyond standard SMTP checks to assess deliverability at the address level.

Example:

anymailfinder.com is configured as a catch-all domain:

Both emails are on the same catch-all domain, but only one shows sufficient deliverability signals.

Simpler tools would label both as RISKY or both as VALID.

Anymail Finder differentiates between them with confidence.

Can I trust VALID results on catch-all domains?

Yes. When Anymail Finder marks an email as VALID, it means we've detected strong signals that it can receive emails, even on a catch-all domain.

If we can't confirm deliverability with confidence, the email is returned as RISKY instead of guessing.

Need help?

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

We're here to help 😊

Updated on: 15/01/2026