A seed list is a set of test inboxes used to check inbox vs spam placement across providers. Learn how seed tests work and their limitations.
A seed list is a collection of test email addresses across different mailbox providers used to check where an email lands (inbox, spam, promotions) before or during a campaign. It’s a practical way to spot formatting issues and major filtering problems.
Seed testing can reveal provider-specific behaviors, like how Gmail categorizes your message or how Outlook treats certain links. It’s most useful when combined with authentication checks and content review.
Seed lists are not perfect predictors of real-world performance because real recipients behave differently and reputation is audience-dependent. Use seed tests as an early warning system, not a guarantee.