What’s Catch-all Email Validation?
When Verify+ is enabled on your account or list, ZeroBounce automatically performs an extra step called Catch‑all Email Validation. This step runs only if there are at least 10 catch-all emails identified in the initial validation (phase one). Its goal is to reduce the number of unresolved catch‑alls by applying deeper models and additional signals.
How it works
Trigger: After Phase 1 (Bulk Validation) is completed, if your results include at least 10 catch-all addresses, we proceed to Phase 2: Catch-all Email Validation for those addresses.
Progress: You’ll see a progress card in the results. During processing, it shows a status message (“Analyzing your catch‑all emails… This process can take up to 48 hours to complete.”).
Results: When complete, some catch‑alls may become Valid or Invalid; the remainder will stay Catch‑all.
Where you’ll see it in the UI
Results page → Phase 2: Email Validation Catch‑All panel with the donut chart
You can download the results once Phase 2 is complete to obtain the latest classifications.
How to disable it
You have the option to disable the Catch‑all Email Validationⓘ feature by deselecting the corresponding checkbox in the final pop-up during the file upload process. Once deselected, the uploaded file will not proceed to Phase 2, and catch‑all addresses will not undergo additional validation.
Catch-All Validation Notes & FAQs
Disclaimer: Catch-all domains are among the most challenging to validate, as they often use multiple layers of filtering (sometimes three or four). These filters can occasionally affect validation accuracy, leading to slightly less reliable results. Always exercise caution when sending to addresses marked as valid after Catch-All Verification.
Scope: To reduce the number of unresolved catch‑alls.
Timeline: Processing may take up to 48 hours, depending on list size and domain behavior.
Data privacy: All processing is performed in‑house; we do not share your data with third parties.
