Technical Comparison

ZeroBounce vs EmailAddress.ai

The B2B Verification Guide: Why the "Unknown" status is costing you revenue.

Executive Verdict

ZeroBounce is an industry giant perfect for B2C lists. However, EmailAddress.ai is engineered specifically for B2B revenue teams, offering 35% higher resolution on corporate catch-all emails that ZeroBounce marks as "Unknown".

Last Updated: October 2024

The Core Problem: The "Unknown" Tax

If you are sending to corporate domains (B2B), you have likely noticed a status called "Unknown" or "Catch-All" in your ZeroBounce reports. On average, 30-40% of B2B email lists fall into this category.

ZeroBounce is conservative. To protect their own infrastructure, they often mark any domain with a firewall (Barracuda, Mimecast, Proofpoint) as "Unknown". For a marketer, this is a dead end. You can't send to them safely, but deleting them means throwing away potential revenue.

The Cost of Unknowns

If you upload 10,000 leads to ZeroBounce, and 3,000 are "Unknown", you effectively paid full price to validate only 70% of your list.

Technical Difference: Deep-SMTP vs Standard Ping

ZeroBounce relies on standard SMTP handshakes. If a server takes too long to respond or sends a generic "Accept All" signal, ZeroBounce categorizes it as Unknown/Catch-All and stops.

EmailAddress.ai uses a proprietary Deep-SMTP™ engine. When we encounter a catch-all signal, we don't stop. We initiate a secondary analysis phase:

  • Latency Fingerprinting: We measure the time-to-first-byte (TTFB) variations between valid and invalid users on that specific domain.
  • MX Preference Logic: We analyze secondary MX records that often have looser security policies than primary gateways.
  • Historical Signals: We cross-reference the domain against our global network of delivery data.

Result: We resolve approximately 95% of the "Unknowns" that ZeroBounce leaves behind.

Feature ZeroBounce EmailAddress.ai
Catch-All Resolution Returns "Unknown" status Resolves to Deliverable/Undeliverable
Greylist Handling Standard Retry (15m) AI-driven Behavioral Retry
Data Enrichment Paid Add-on (Scoring) Included (Name, Company, Job)
Pricing Model Credits Expire Annually Credits Rollover Monthly
Support Focus General / B2C B2B / Cold Outreach

Pricing Comparison

Beyond accuracy, pricing structure matters. ZeroBounce charges a premium for their brand name. EmailAddress.ai offers a leaner, infrastructure-first pricing model.

ZeroBounce

$65
per 10,000 credits
  • Credits often expire
  • Pay extra for enrichment
Best Value

EmailAddress.ai

$45
per 10,000 credits
  • Credits rollover forever
  • Enrichment included

Pros & Cons

ZeroBounce Pros

  • • Excellent UI and documentation
  • • 24/7 Chat Support is very responsive
  • • High accuracy on Gmail/Yahoo/Hotmail
  • • Email Scoring feature (AI) is solid

EmailAddress.ai Pros

  • • Superior resolution of B2B Catch-Alls
  • • Lower cost per verification
  • • Includes enrichment data at no extra cost
  • • Rollover credits on subscriptions

Frequently Asked Questions

Yes. A common strategy for enterprise teams is to use ZeroBounce for their B2C lists (consumer emails) and EmailAddress.ai for their B2B lists to maximize yield on corporate domains.
Yes. Our API is designed to be a drop-in replacement. We use standard REST conventions and JSON responses. Migration typically takes less than an hour for a developer.
ZeroBounce spends heavily on marketing and offers a very broad suite of tools (blacklist monitoring, server testing). We focus strictly on verification infrastructure, passing the savings to you.

Ready to see the difference?

Run a free test on your hardest list. See how many "Unknowns" we resolve into "Deliverable" leads.

Get 100 Free Credits View Pricing