BounceBlock.io
Detect Catch-all Domains

Detect Catch-all Domains in two minutes

Catch-all domains (sometimes called accept-all domains) are configured to accept every incoming SMTP connection regardless of whether a valid mailbox exists — which means standard SMTP verification returns a passing result for addresses that may not actually be deliverable. This is one of the most technically nuanced challenges in email verification: an address at a catch-all domain cannot be confirmed or denied through the usual handshake, and blindly mailing these addresses increases bounce risk substantially. Proper catch-all detection requires separating this ambiguous category from confirmed-valid addresses so you can make an informed decision about your risk tolerance.

100 free creditsNo credit cardResults in under 2 min
6
Deliverability checks per address
Email + phone
Validated in one upload
Under 2 min
Average list clean-up time
100 free
Verifications, no card required
The problem

What's hiding in your list

A domain that behaves as catch-all today may not be configured that way tomorrow — domains switch their MX and catch-all settings as IT policy changes, so a cached result from six months ago may no longer be accurate.

Many enterprise domains are catch-all by default for all subdomains or legacy addresses, meaning a large B2B list targeting mid-market companies may have 30–40% catch-all coverage with no obvious pattern.

Treating all catch-all addresses as invalid causes you to suppress potentially valid enterprise contacts; treating them all as valid causes you to mail addresses that bounce — there is no risk-free binary answer.

Why BounceBlock

Email and phone — cleaned in one pass

Verify in one pass

Every email checked for deliverability and every phone validated — in a single upload.

Catch what others miss

Typos, catch-all domains, disposable addresses, dead numbers and silent duplicates.

Flat, simple pricing

Flag risky catch-alls before you send. No per-credit math, no surprise overage bills.

How it works

Clean leads in three steps

No setup, no integrations, no learning curve. Upload a file, download a better one.

1

Upload your CSV

Drag in any contact list. We auto-detect email, phone, name and company columns.

2

We verify everything

Every email checked for deliverability, every phone validated, duplicates flagged — with a live quality score.

3

Download clean leads

Export a verified, deduplicated list your team can actually call and email.

Now onboarding early teams

Email and phone, cleaned in a single upload — see exactly how many bad contacts are hiding in your list before you pay a cent.

100 free verifications · no credit card · results in under 2 minutes

Questions

Frequently asked

What is the best strategy for mailing catch-all addresses?

Segment them separately and mail them at a lower volume or with a longer warm-up cadence; monitor bounce rates on that segment in isolation so you can adjust the threshold for future campaigns without contaminating results from your confirmed-valid segment.

Can any tool definitively verify an address on a catch-all domain?

No — by definition a catch-all domain accepts the SMTP connection before any mailbox check, so the only reliable confirmation is receiving an actual bounce or engagement signal after a real send.

How does BounceBlock label catch-all addresses in its results?

Catch-all addresses receive their own status flag and quality score that reflects the domain-level risk, so you can filter or segment them independently from hard-invalid addresses rather than lumping both into a single reject bucket.

Stop wasting hours on dead leads.

Upload your list and see how clean it really is — free, in under two minutes.

100 free creditsNo credit cardCancel anytime