Getting Started
Why a "safe" email might still bounce
What "safe" means
When OrbiSearch marks an email as "safe," it means we found a conclusive or high-confidence signal that the mailbox exists and is accepting mail. This is the strongest verification result possible without actually sending an email.
Why a verified email can still bounce
All email validation tools, including OrbiSearch, verify whether a mailbox exists. But a mailbox existing is not the same as your email being delivered to it.
After a mail server accepts an incoming message, additional layers of filtering and policy can reject or discard it. These happen after the point where validation operates, and no email validation tool can see them without sending a real email. Common causes include:
- Allowlist or sender policy restrictions. Some organisations, particularly enterprises, configure their mail servers to only accept email from pre-approved sender domains. The mailbox exists, but your domain is not on their approved list.
- Content or reputation filtering. Corporate email gateways may reject messages after acceptance based on content analysis, sender reputation scores, or anti-spam policies.
- Mailbox changes after verification. A mailbox that existed at the time of validation may be disabled, migrated, or deleted before you send your campaign.
Can any tool guarantee 100% deliverability?
No. Every email validation provider operates under the same fundamental limitation: verification confirms whether a mailbox exists at the moment of verification, not whether your specific email will be delivered to it. Any provider claiming 100% accuracy is overstating what email validation can do.
OrbiSearch has market-leading accuracy, validated against real campaign data from cold outreach campaigns. Our dual-layer verification catches more invalid addresses than traditional validators, but post-acceptance filtering is outside the scope of what any validation tool can detect.
What should I do if a "safe" email bounces?
Check the bounce reason in your email sending platform. If the bounce message references a policy block, allowlist restriction, or content filter, the issue is on the recipient's side, not a validation error. The mailbox exists, but the recipient's administrator has configured rules that prevent delivery from your domain.
If you believe there is a genuine validation error, contact support with the email address and bounce details and we will investigate.