B2B ICPs drift into the long tail of providers: European companies on GMX/Web.de, Indian SMBs on Zoho, privacy-conscious users on ProtonMail, Apple-ecosystem users on iCloud. A placement test that only covers Gmail and Outlook misses a measurable share.
Providers we actively seed
- iCloud / me.com / mac.com — Apple's mail, with its own content filtering and heavy dislike of tracking pixels.
- ProtonMail — privacy-first, content-scanned, TLS-strict.
- GMX — big in DACH region. Bayesian filter + reputation.
- Web.de — sister to GMX (same operator, different sub-filters).
- Zoho Mail — heavy SMB usage in APAC; SpamAssassin-style content filter.
- AOL — still exists, still classifies.
- T-Online — German ISP mail.
- 1&1 / IONOS — business mail hosting.
Why the tail matters
- German and Austrian B2B ICPs have 10–25% on GMX/Web.de/T-Online. Ignoring them skews the picture.
- Indian and SEA B2B ICPs have 10–30% on Zoho.
- Privacy-leaning niches (security, crypto, policy) over-index on ProtonMail.
- Apple-ecosystem solopreneurs often list iCloud on public contact pages.
Provider-specific gotchas
- iCloud penalises tracking pixels aggressively. Turn off for Apple-heavy ICPs.
- ProtonMail rejects mail over plain TLS if its end knows yours supports TLS 1.3. MTA-STS helps.
- GMX/Web.de tighten on low-content or image-only mail. Write real text.
- Zoho weighs sender frequency; first-touch to Zoho should be modest.
Test the whole tail
Run a free test. Providers auto-selected or filter to your target ICP's mix.
FAQ
Will you add more providers?
Yes — the network grows as ICP requests come in. Email us for specific provider requests (we've added five in the last year on customer request).
Are iCloud seeds real Apple IDs?
Yes — real Apple IDs with active mail. Apple is particularly good at detecting simulated accounts.
Do all providers expose folder status?
Most expose Inbox vs Spam. Category-style sub-folders are Gmail/Outlook-specific; other providers report the simpler binary plus occasional 'Promotions' equivalent.
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