Concerns About Email Validation Accuracy and False Negatives

Denver B. · 2025-11-20T09:51:17.625Z

Hey, On the email validation waterfall, it works a bit differently by going through all validation providers even if the first one has been found. And it seems that all 7 sources needs to be validated for it to come through. Is there a chance that this could provide a false negative? In other words, if one validation source is inaccurate and comes back as false, this could lead to the final output as wrong Is there a particular source which is seen as more accurate?

Concerns About Email Validation Accuracy and False Negatives | Clay

Clay Support
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The email waterfall doesn't validate through all providers - it stops when a valid email is found. Multiple providers only run when the email found is invalid, causing the next provider to run until a valid email is found.
By default, we use ZeroBounce as our validation provider, known for high accuracy. [1] You can choose a different validation provider if you prefer one that validates better for your specific industry.
False negatives are unlikely since only one validation step determines the final result - not multiple validators that could conflict.
Clay Support
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Clay Support
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If you need any further clarification or assistance with the email validation process, I’m here to help. Would you like to provide more details about what you’re trying to resolve or understand?
Asher
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Denver B. Sounds like you are using the typical Clay waterfall, where for every email finder you use, you validate with zero bounce. And it seems like zero bounce shows valid, but yet it goes to the next email finder, which then wastes credits. Not sure if that’s what you’re experiencing?
Clay Support
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That's not how our email waterfall works. The waterfall stops when a valid email is found - it doesn't continue to the next provider.
Multiple providers only run when the email found is invalid, causing the next provider to run until a valid email is found. If a provider finds a valid email, the process stops for that contact. [1]
If ZeroBounce shows valid but the waterfall continues, check your validation settings - toggles like "Only Safe to Send emails as valid" might be limiting acceptable results.
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Asher
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To give more context- By default, Clay turns on the ‘Only Safe to Send emails as valid’ settings. And when it comes to email validation, there are generally 3 broad categories. Valid Catch All Invalid The ‘Only Safe to Send emails as valid’ settings essentially treat catch-all emails as invalid, which results in it going to the next email finder.
Clay Support
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You're correct about how the "Only Safe to Send emails as valid" setting works. When enabled, this setting treats catch-all emails as invalid, causing the waterfall to continue to the next email finder. [1]
The three email validation categories are:
- Valid: Specific, active addresses that can successfully receive emails
- Catch-all: Domains that accept all email addresses, even ones that may not be monitored
- Invalid: Emails that don't exist [2]
With "Only Safe to Send" enabled, catch-all emails don't meet the validation conditions, so the system moves to the next provider to find a "valid" email instead. This explains why you're seeing the waterfall continue even when an email is found but classified as catch-all.
Clay Support
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Clay Support
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If you still need help understanding the email validation waterfall or its settings, I’m here to assist. Would you like to share more about what you’re trying to resolve or clarify?
Denver B.
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I am using this which goes through all the providers. It seems you recommended ZeroBounce as a provider source?
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Clay Support
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Yes, we recommend ZeroBounce as our default validation provider because it's a best-in-class service with 99.25% data quality and 99.37% coverage. [1]
Your setup shows all validation providers running sequentially, which differs from our standard email waterfall that stops when a valid email is found. [2] This configuration validates the same email through multiple providers, which may consume more credits than necessary.
ZeroBounce remains our top recommendation for accuracy, but you can choose any provider that works best for your specific industry needs. [3]
Clay Support
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Is that what you were looking for?
Clay Support
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If you need any further help with your email validation setup or want to discuss optimizing your provider configuration, I’m here to assist. Would you like to provide more details about what you’re trying to achieve or any specific concerns you have?
Denver B.
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thanks, will use zerobounce as the priority source

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