Deliverability
What is Seed List?
A set of monitored test inboxes across major providers used to measure where your email actually lands.
A seed list is a curated collection of test mailboxes spanning providers (Gmail, Outlook, Yahoo, and corporate systems) that you send a campaign to in order to observe placement. A deliverability tool then reports whether each copy hit the inbox, the spam or junk folder, or a tabbed category, along with authentication results. It measures placement among the seeds, not real engagement, so it complements rather than replaces signals from live recipients.
Why it matters for cold email
Seed-list tests let cold senders catch a spam-folder problem before burning real prospects, and verify that warmup, content, and authentication changes actually move placement. The caveat is that seeds never open or reply, so over-reliance on them can mask reputation issues that only surface with live recipients.
Related terms
Stop guessing at deliverability.
Scheduler Zero handles authentication, warmup, and sender reputation so your cold email lands in the inbox, not the spam folder.