The most important thing about a placement test is the seed network behind it. Tiny networks over-fit to one or two provider flavours; networks inside a warmup pool grade themselves. Our network is big, independent, and diverse by design.
Network summary
- 4,000+ active mailboxes.
- 30+ providers: Gmail, Gmail Workspace, Outlook, Outlook.com, Hotmail, Live, Microsoft 365, Yahoo, AOL, Mail.ru, Yandex, Rambler, List.ru, ProtonMail, iCloud, GMX, Web.de, Zoho, and more.
- Every seed mailbox is real — a registered account on the real provider, not a simulated endpoint.
- No mailbox participates in any warmup pool.
- Geographic distribution: EU, US, CIS, UK, APAC.
Why 4,000+ is the right number
- Provider-level averaging needs sample size. A single Gmail seed's result is noise; 50+ gives you signal.
- Anomaly detection: a single mailbox behaving unusually is suppressed by the aggregate.
- Provider variant coverage: Gmail consumer, Workspace business, Workspace EDU, Workspace non-profit — each is its own sub-population that needs seeds.
- Geographic variation: Gmail in Germany behaves differently than Gmail in Brazil at the filter level. Regional seeds catch regional bugs.
Outside every warmup pool — by design
We never register seed mailboxes into warmup pools. We never auto-accept mail from pool senders. We never trigger mark-as-important on pool-origin messages. This is the property that makes the placement number meaningful — if the seed is in the pool being tested, the number grades itself.
Keeping the network fresh
- Mailboxes rotated on a schedule so filters don't over-train on them.
- Provider-level hygiene: occasional organic engagement to keep each mailbox looking like a real user.
- Usage caps per mailbox per 24h to prevent filter desensitisation from test-only traffic.
Use the network
Run a test. Free, no signup, every seed we have.
FAQ
Why don't competitors disclose pool vs non-pool network?
Because most of them have warmup products too, and admitting the seed network is inside the pool would invalidate their placement numbers. We don't have a warmup product, so there's nothing to hide.
Can I target specific seeds for my test?
You pick providers; we pick seeds within each provider to distribute load and protect mailbox freshness. The per-provider aggregation is what you want anyway.
Can I add my own mailbox to the network?
Partner program in beta. Email us if interested.
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