11

FAQs

Last Update 14 dagen geleden

Verifying emails that are accept-all or protected by SEGs Our guarantee Is single email verification really free? Do you provide APIs? Email verification score and states

Verifying emails that are accept-all or protected by SEGs

Eric Martin

Last Update 5 maanden geleden

What is accept-all (catch-all)?

Email domains that have configured accept-all (or catch-all) filters would return the status code of 250 OK for all email addresses at that domain, existing or not. As a result, those email addresses cannot be verified in the traditional way, and most email verification services have to mark all those emails as risky as they cannot provide a reliable result.

What's SEG (Secure Email Gateway)?

For increased email protection, many organizations may use SEG, like Proofpoint, Minecast, etc. An SEG works by acting as a proxy for an organization's email servers. The SEG can filter and inspect email for malicious content before forwarding emails to the intended recipient. As a side effect, SEG also makes email verifications harder, if not impossible, for most email verification service providers. 

How BounceBan verifies emails that are accept-all or protected by SEGs?

BounceBan does not simply mark all the emails that are accept-all or protected by SEGs as "risky" like others do. Instead, it has developed a special algorithm that can detect and analyze many signals to reliably determine the true deliverability of those emails. 


BounceBan guarantees that it can reliably verify 83%+ of email addresses that are accept-all or protected by SEGs (Secure Email Gateway) with a 97%+ accuracy, and the rest that cannot be reliably verified will be marked as "risky". As a result, you'll get more emails correctly marked as "deliverable" or "undeliverable" depending on your list quality, and fewer emails marked as "risky", while still achieving the similar level of guaranteed delivery rate.


Learn more about our guarantee here: https://bounceban.tawk.help/article/our-guarantee

How do other email verification services verify emails?

Most email verification services rely on SMTP testing to verify email addresses. However, this method has significant limitations:


Catchall Domains: Many business email domains are configured as catchall, meaning they accept all emails sent to them, making all addresses appear "valid" in SMTP tests. This is why many services label these emails as "Risky."

Email Security Gateways (ESGs): Many business email domains are protected by ESGs (such as Mimecast, Barracuda) or hosted by services with advanced routing options like Office 365. Administrators can configure these systems to return Non-Delivery Reports (NDRs) only for specific cases (e.g., unknown senders) or not at all for others (e.g., ex-employees). Consequently, relying solely on SMTP testing is unreliable for determining email validity.


BounceBan uses SMTP testing as one of many signals to determine the final state of an email. Our comprehensive approach ensures higher accuracy by considering multiple verification factors.

I sent a test message without a bounce, but BounceBan says it's an undeliverable email. Can I trust you?
The absence of a bounce or Non-Delivery Report (NDR) after sending a test message does not guarantee the email address is valid. Modern business email solutions like Office 365 or Google Workspace allow administrators to configure advanced NDR policies, such as not returning NDRs for unknown senders or specific email groups (e.g., ex-employees). This makes NDRs an unreliable indicator of email validity. Consequently, services that verify emails by sending actual messages may fail to detect invalid emails in these cases.


You can verify this by checking the email owner's LinkedIn profile or another trusted source to see if they are still employed at the company associated with the email domain.


BounceBan is not perfect, but our extensive real-world testing demonstrates an average accuracy rate of around 97%. If you believe there has been an error, please let us know by clicking the Report Problem link.

I sent a message to an email marked as "Deliverable" by BounceBan and it bounced. Can I trust you anymore?
To understand why a message bounced, we need to examine the bounce message (NDR). Some NDRs indicate the sender is blocked (spam reports), suggesting the email address is valid but not accepting messages from the sender. Other NDRs may relate to security policies (e.g., not receiving external messages). In some cases, NDRs signify that the email address is indeed invalid, indicating a mistake on our part.


While BounceBan strives for perfection, mistakes can happen. Our real-world testing shows we achieve an average accuracy of around 97%. If you believe we made an error, please don't hesitate to let us know by clicking the Report Problem link.

Was this article helpful?

6 out of 6 liked this article

Still need help? Message Us