Yes, if you send unverified catch-all addresses from your main domain, mixed into your main campaign: a share of them will bounce, and bounces hurt sender reputation. No, if you verify them first, or isolate them in a separate, low-volume campaign on secondary domains. A catch-all result means unconfirmed, not invalid, so deleting them all wastes real contacts.
The Short Answer, by Situation
The right move depends on the domain you send from, how much mail it already carries, and what each contact is worth.
| Situation | What to do |
|---|---|
| New or fragile sending domain | Skip the catch-all rows, or verify them before any send |
| Main domain, already sending at high volume | Do not send unverified catch-alls from it |
| Healthy secondary domains, at a lower volume | Send catch-alls as their own campaign and watch bounces |
| High-value accounts | Verify first, then decide |
A result labeled Unknown is a different bucket: the check did not return a usable answer. What to do with those rows is covered in how to validate unknown emails.
What “Catch-All” Means on a Cold Email List
A catch-all domain, also called accept-all, accepts mail for any address at that domain. An SMTP check asks whether the mailbox exists, and the server says yes either way, so the result is unconfirmed, not invalid. Some addresses deliver to a real person, some land in a catch-all inbox nobody reads, and some bounce later, after the server has already accepted the message.
How SMTP verification works, and where it fails walks through the handshake, and why SMTP tools cannot validate risky emails is the short version. Exports often call the same rows risky: catch-all vs risky. For the longer definition, see what a catch-all email account is and the ultimate guide to catch-all emails. Owning a catch-all inbox is a separate job, covered in how to set up and manage a catch-all email address. For background, see the broader risks and rewards of catch-all addresses.
How common is the setup? Hunter reported that 38% of domains were accept-all in an analysis of 2,572 addresses, and said the share varies by industry and location (Hunter, accept-all guide, 4 November 2025). That is Hunter’s sample. It is not a rate you can paste onto every list.
Why Sending Unverified Catch-Alls Is Risky
They bounce more often than confirmed addresses. In a separate Hunter send test, 100 accept-all addresses were compared with 100 valid ones. The bounce rate was 27% on the accept-all group and 1% on the valid group. It is a small sample, and it is Hunter’s test, not ours. FullEnrich, which does send to catch-all addresses, says about 10% of the catch-all addresses it sends to bounce (should I send emails to catch-all addresses, June 2024).
Those bounces count against the domain and the mailboxes that sent them. A hard bounce is permanent. A soft bounce is temporary, until the same address keeps failing. Soft bounce vs hard bounce is the distinction, and bounce rate benchmarks by industry is where the published lines sit. How the volume shows up in placement is in catch-all emails and their impact on deliverability. What happens if you do not validate risky emails is the short version of skipping the check.
Some mail a catch-all server accepts never reaches a person. It sits unread: no bounce, no reply, and the row still looks fine in the sequencer.
Why Deleting Every Catch-All Is Also a Mistake
Catch-all rows can be a large share of a B2B list. FullEnrich says large organizations use catch-all setups more often than smaller firms, and that about 20% of its own audience is catch-all. Deleting the whole bucket shrinks the file without telling you which addresses belonged to real people.
Your Options, from Safest to Riskiest
Verify Them First
On Scrubby the usual order is two passes. The second is only for what the first cannot settle.
Quick Verification costs 1 credit per email. It confirms deliverability on standard, catch-all, and SEG-protected domains in minutes, with a handshake plus a catch-all probe. Run it across the whole list.
Deep Verification costs 3 credits per email and is for addresses that stay uncertain. Scrubby sends a real blank email to each of them from its own warmed infrastructure. Your domains are never used. It watches responses for 72 hours, including delayed bounces. Most addresses resolve in the first 24 hours. First results are in at 24 hours, and the final result is in at 72 hours. How long catch-all verification takes collects that timing.
Copy the workflow on the Deep Verification page: Quick Verification on everything, then Deep Verification only for what comes back uncertain.
ZeroBounce’s status-code docs say a catch-all address is “impossible to validate without sending a real email and waiting for a bounce” (status codes). Deep Verification is aimed at that gap, and the send uses Scrubby’s infrastructure rather than the domain your customers already know. Hunter’s guide treats a test email as a method that raises ethical concerns, because a test from your own outreach is unsolicited mail. Read the result before the address goes into a campaign. If another tool already marked the rows risky or catch-all, start from risky email validation.
Blaise G., VP of Sales at Neptik, wrote on our pricing page: “Scrubby is the only email validation software that doesn’t give you ‘unknown’ emails.” That is a customer’s description of his experience, not a promise that every address comes back valid.
Send Them as a Separate Campaign
If you are not verifying first, keep these rows out of the campaign on your main domain.
- Verified addresses go from your main sending setup, at the volume it already handles.
- Catch-all addresses go from warmed secondary domains, at a lower volume, with the same SPF, DKIM, and DMARC you use on the main domain.
- If a domain’s catch-all addresses bounce, suppress that domain.
How to set up a separate domain for cold email is the domain setup. Validating a list before a Smartlead campaign is where the file meets the sequencer. Hunter’s accept-all guide offers a different containment figure, about 2 to 5 percent of a mixed campaign. That is Hunter’s number, not one Scrubby has measured, and even a small mix still puts bounce risk on the sending domain.
Reach Them on Another Channel
For a few high-value contacts, an unconfirmed email is a weak first touch. LinkedIn or a phone call can reach the person without a bounce on a sending domain.
Skip Them
Skip the catch-all rows when the sending domain is new, or when you are still rebuilding one. A domain without a reputation cannot absorb a bounce spike. If the export came from ZeroBounce, what to do with ZeroBounce catch-all results is written for that file.
How to Decide for Your List
Four questions choose among the options above.
- How healthy is the sending domain, and how old is it? A new domain, or one you are repairing, should not carry unverified catch-alls. Verify the rows, or leave them out.
- How many emails a day, and from which domain? FullEnrich’s rule: if you send over 1,000 emails a day from the primary domain, do not send unverified catch-alls from it. That comes from their own sending. It is not a threshold Scrubby has set.
- What share of this list is catch-all? A handful of rows is a different decision from a large slice of the file. There is no published share at which you must stop.
- What is each contact worth? A named buyer at an account you already care about can justify a Deep Verification credit. A guessed address at a company you have never spoken to often cannot.
What It Costs to Verify Catch-Alls Before You Send
Monthly plan rates on the pricing page, with Quick Verification at 1 credit and Deep Verification at 3. The per-1,000 columns are those rates applied to 1,000 addresses.
| Plan | Monthly price | Credits | Per credit | Quick, per 1,000 | Deep, per 1,000 |
|---|---|---|---|---|---|
| Starter | $47 | 6,000 | 0.78¢ | $7.80 | $23.40 |
| Growth | $97 | 15,000 | 0.64¢ | $6.40 | $19.20 |
| Pro | $497 | 100,000 | 0.49¢ | $4.90 | $14.70 |
Pay-as-you-go on the same page is $0.008 per credit, which is $8.00 per 1,000 addresses on Quick Verification and $24.00 per 1,000 on Deep Verification. New accounts receive 200 free credits, and no card is required to start. On monthly plans, unused credits roll over for as long as the subscription stays active.
The recommended workflow costs the whole list at Quick Verification, plus only the uncertain rows at Deep Verification:
credits = (list size × 1) + (uncertain rows × 3)
Multiply that total by the per-credit price on your plan.
Example only, not a measured share: 2,000 addresses, with 400 treated as still uncertain after Quick Verification. The 400 is a round number so the arithmetic is easy to check. It is not a Scrubby result.
- Quick Verification: 2,000 credits
- Deep Verification: 400 × 3 = 1,200 credits
- Total: 3,200 credits
At Growth’s 0.64¢, 3,200 credits is $20.48. The same total is $24.96 on Starter and $15.68 on Pro. Swap in your own list size and uncertain count. Do not reuse 400 as if it were typical.
What to Watch After You Send
If a catch-all campaign does go out, read it on its own. An average across every campaign hides the domain that is taking the bounces.
- Bounce rate for that campaign, and for the domain that sent it.
- Replies next to bounces on the catch-all campaign. Replies mean the segment is reaching people. Bounces name the domains to stop.
- Suppress any domain that bounces before the next batch.
ReplyLabs describes keeping the safe campaign’s bounce rate under 2 percent, with the catch-all send isolated so the variance stays off the main domain (how to handle catch-all emails in cold outreach). That 2 percent is their aim for the verified campaign. It is not a Scrubby rule, and it is not a line measured here for catch-all sends. Industry ranges live on the benchmarks post linked above.
FAQ
Are catch-all emails valid? They’re unconfirmed. The server accepts any address at the domain, so a normal check can’t tell whether the mailbox exists.
Will sending to catch-all addresses hurt my deliverability? It can if they’re unverified, mixed into your main campaign and sent from your main domain, because some will bounce. Verified or isolated, the risk is much smaller.
Should I delete catch-all emails from my list? Not all of them. Many are real contacts. Verify them, or send them separately and suppress what bounces.
How do you verify a catch-all email? A standard SMTP check can’t. Scrubby’s Deep Verification sends a real blank email from Scrubby’s own infrastructure and watches for bounces for 72 hours.
How much does it cost to verify catch-all emails? With Scrubby, $14.70 to $23.40 per 1,000 addresses on Deep Verification, depending on plan, and less if you run Quick Verification first and send only uncertain results to Deep.
Verify the catch-all rows on the list you are about to send. New accounts start with 200 free credits, and no card is required. See pricing.
Nick Abraham
Cold Email Expert