In the whirlwind of online marketing, each email matters. But when almost 50% of B2B databases are catch all emails, marketers have a specific problem. Catch-all email addresses (also called accept-all or wildcard emails) are set up at the domain level to receive mail sent to any address—even if the specific account doesn’t exist.
On its face, this sounds handy: no more lost emails because of misspellings. But for marketers, it generates a massive deliverability blind spot. Old-school checks won’t validate if a particular inbox exists, so some of your list could be undeliverable and you wouldn’t know it.
The result? Increased bounce rates, decreased engagement, poor sender reputation, and in extreme cases-blacklisting.
What Are Catch-All Email Addresses?
Catch-all settings tell mail servers to receive all mail sent to their domain, even if the username doesn’t have a mailbox. For example, a domain with catch-all settings would receive mail to randomuser@company.com, invalidname@company.com, or anythingatall@company.com–whether these accounts exist or not.
This set-up has it’s valid uses for companies looking to make sure they don’t miss e-mails from typos or old addresses. But it makes things hard for email marketers struggling to keep lists clean and track deliverability.
Why Validate Catch-All Email Addresses?
Before we dig into the “how,” let’s address the “why.”
- Catch-Alls Are Extremely Common
Studies show that 42% of B2B email lists include catch-all domains. That’s almost half of your prospects hanging in the balance. Dismissing them is missing out. - Bounce Risk Is Real
Unverified catch all emails can push bounce rates above 9%, damaging your sender score. Any more than 2% and you’re already raising a red flag with ESPs. - They Hide High-Value Prospects
Surprisingly, verified catch-all addresses often yield 67% higher engagement rates compared to regular contacts. Why? Since numerous corporate mail servers employ catch-all emailfor security, those addresses are frequently owned by actual decision-makers. - Reputation & Spam Risks
Sending to invalid catch alls can trigger spam traps, leading to blacklisting, poor inbox placement, and wasted campaign budgets.
In other words: verify catch all emails isn’t a choice — it’s the basis of email marketing victory.
Step 1: Know catch all email behavior
A catch-all domain receives all email to it. For instance:
- Sending to abc@company.com (doesn’t exist) → Accepted
- Sending to test@company.com (doesn’t exist) → Accepted
The mail server always returns a successful (SMTP 250) code, making traditional checks useless.
Why it matters: If you rely only on syntax/domain checks, you’ll never know which addresses are deliverable. That’s why sophisticated verification mechanisms and layered testing are so important.
Step 2: First List Scrub, with Basic Tools
So the first step is rinsing your database with a broad validation service. These tools classify emails into:
- Valid → Safe to send
- Invalid → Should be removed
- Catch-All / Unknown → requires further catch-all email validation
Tools you can use:
no2bounce → Excellent for shrinking the ‘unknown’ bucket significantly. Its AI detection and bulk validation speed give marketers a sharper edge. And with credits that never expire, it’s super cost effective.
NeverBounce → Accurate on easy tests but generally answers ‘unknown’ for catch all.
ZeroBounce → Has fraud/scoring layers but catch-all precision is limited.
Mails.so → Inexpensive and bright, stamps catch-alls distinctly.
Pro tip: Run No2Bounce through here to catch dangerous catch-alls early. It avoids wasted effort on notes that will never arrive.
Step 3: Employ sophisticated catch-all validators
Once your list is scrubbed, the real challenge begins — catch-all verification. Simple tooling ends at flagging them, but custom software extends with ML, risk alerts and proactive audits.
Recommended tools:
no2bounce → Goes beyond most with its combo of real-time check, AI scoring, and domain-level insights. So many marketers rave about No2Bounce for catch-all detection, saying it trumps ZeroBounce and the others.
Scrubby → uses “burner accounts” to test catch-alls, as accurate as 98%
Allegrow → uses 30+ signals (including patterns of engagement) for safe vs unsafe decisions.
DeBounce → Uses its own algorithms to save 20–30% of dangerous leads.
Anymail Finder → Continue testing catch-all domains for deliverability
Step 4: Alternative Validation Techniques
Or if you don’t want to depend entirely on tools you can sprinkle in manual check points.
Google People Chips Way → dump emails into google sheets, if an e-mail is associated with a google account, it’s probably legit.
Quick Mail + LinkedIn Cross-check → Look up address permutations to confirm with social profiles.
PhantomBuster workflows —> Scrape linkedin and match against catch-all emails
These are effective but time-consuming. Matching them to no2bounce automation is the most efficient way to scale.
Step 5: Segment & Test
Once agreed, don’t open all catch all emails simultaneously. Instead:
High-Stakes Campaigns → use only “safe” catch-alls verified with no2bounce, Scrubby, or Allegrow.
Re-Engagement Campaigns → Test small segments with nurturing e-mails before you blast broadly.
✅ no2bounce syncs with favorite ESPs (think CRM, HubSpot, Clay) so segmentation and experimentation flow seamlessly.
Step 6: Monitor & Maintain List Health
- Validation is not a 100 yard dash. E-mails rot at 22% annually, so you need constant scrubbing.
- Validate every 3-6 months or before big campaigns.
- Track engagement (opens, clicks, unsubscribes).
- no2bounce API for realtime verification at point-of-entry.
- Use double opt-in for new subscribers.
BONUS pro tip: no2bounce’s real-time check and bulk email verification features keep your database healthy in the long term.
Risks of Skipping Catch-All Validation
If you ignore this process:
- Bounce rates spike → sender score nosedives
- ESPs throttle your campaigns
- Leads lost to hidden invalids
- Marketing spend is wasted
Conclusion
Catch all verification is not a nice to have anymore, it is a need to have to capture lead potential, minimize bounce and protect your sender reputation. From old school verifiers, to cool catch all verifier like Scrubby or Allegrow, to sneaky hacks like Google People Chips or newsletter testing — marketers can reclaim up to 30% more leads and keep campaigns safe.
But to do it reliably and at scale you need a trusted partner that abstracts the whole process.) no2bounce preeminence with its enterprise-grade validation engine, catch-all detection and real-time verification APIs—so you never invest in dangerous addresses. Cold outreach, nurturing campaigns, or high-stakes promos — no2bounce delivers your email strategy the accuracy it needs.
👉 Don’t gamble with your campaign results—choose no2bounce catch all email verifier for clever safer and more effective email marketing.
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