Sending guide

Catch-all email addresses: should you email them?

What catch-all domains are, why verification tools can’t confirm them, and how to email them without hurting your domain.

What a catch-all email address is

A catch-all (or accept-all) domain accepts email sent to any address at that domain, even ones that don’t exist. Send to anything@company.com and the server says “yes” at first. That’s why email verification tools can’t confirm these addresses: they come back as “catch-all”, “accept-all” or “unknown”.

Why they matter for cold email

Some bounce later. The server accepts the email, then bounces it after looking it up, which still counts against your bounce rate.
Some go nowhere. Email to made-up addresses can be silently dropped or land in a shared inbox nobody reads.
But many are real people. Lots of companies, especially on Microsoft 365 with security gateways, run catch-all setups. Skipping them all means losing good leads.

How to email catch-all addresses safely

Verify the list first and keep catch-all addresses in their own segment.

Send to them in small batches from a separate campaign, so a spike in bounces doesn’t hit your main sending. Plan the extra inboxes with the cold email calculator.

Prefer addresses with a known pattern, such as firstname@ when other people at that company use firstname@.

Watch the bounce rate and stop the segment if it climbs over 2%. See soft bounce vs hard bounce.