What is Seed Testing?
Seed testing (or inbox placement testing) involves sending emails to test addresses across major providers to verify whether messages land in inbox vs. spam before launching real campaigns.
Seed testing involves sending your emails to a panel of test addresses across different mailbox providers to see where they land—inbox, spam, promotions tab, or not delivered at all. It's essentially a pre-flight check for email campaigns.
How seed testing works: 1. Send your email to test addresses at Gmail, Yahoo, Outlook, etc. 2. Service checks where each test email landed 3. Report shows inbox placement rates by provider 4. Identify issues before sending to real recipients
Seed testing reveals problems invisible in delivery metrics. An email can be "delivered" (accepted by the server) but still land in spam. Seed tests show actual inbox placement, helping you catch authentication issues, content problems, or reputation concerns before they affect your real sends.
Why Seed Testing Matters
Delivery rate doesn't tell the whole story—you need to know if emails reach the inbox. Seed testing catches problems early: a failing DKIM signature, content triggering spam filters, or reputation issues with specific providers. For high-stakes sends or when making infrastructure changes, seed testing provides confidence before committing.
How Ark Handles Seed Testing
Ark recommends seed testing when onboarding a new domain, changing email content significantly, or troubleshooting deliverability issues. We integrate with popular seed testing services and can recommend providers. Our deliverability team uses seed testing as part of our analysis when helping customers optimize their sending.
Frequently Asked Questions
How often should I run seed tests?
Run seed tests before major campaigns, after infrastructure changes (new IP, domain, or provider), and periodically (monthly or quarterly) for ongoing monitoring. More frequent testing for high-volume senders.
Are seed test results accurate?
They're directional but not perfect. Seed addresses are known to testing services, which could theoretically affect filtering. Real inbox placement can vary based on recipient engagement history. Use seed tests as one signal among many.
Why would my email pass seed tests but still have delivery issues?
Seed tests use fresh addresses without engagement history. Real recipients with different interaction patterns may see different results. Also, seed tests happen at one point in time—reputation can change.
What should I do if seed tests show spam placement?
Check authentication (SPF, DKIM, DMARC). Review content for spam triggers. Check IP and domain reputation. Look for issues specific to certain providers. Fix issues and retest before sending.
Related Terms
Email Deliverability
Email deliverability is the ability to successfully deliver emails to recipients' inboxes rather tha...
Spam Trap
A spam trap is an email address used to identify spammers, either recycled from abandoned accounts o...
Email Authentication
Email authentication is the process of verifying that an email was actually sent by the claimed send...
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