If your ICP includes Russia, Ukraine, Kazakhstan, Belarus or the wider CIS, the global tools are not going to cover you properly. The filter stacks are different, the reputation logic is different, and the public diagnostics (Postmaster equivalents) are different.
- Mail.ru — 50M+ active Russian inboxes. FBL-participating seeds, DKIM-strict by provider default.
- Yandex — ML-heavy domain-reputation filter. Seeds across personal + corporate Yandex360 tenants.
- Rambler — small (4% share) but idiosyncratic. Its own filter engine.
- List.ru — shares the Mail.ru Group infrastructure but with separate reputation surfacing.
Why they're a separate problem
- Yandex weights sender age and domain reputation earlier than Gmail; new domains get to Spam faster.
- Mail.ru enforces DKIM strictness more than consumer Gmail — alignment issues that pass Gmail will fail Mail.ru.
- FBL (feedback loop) participation is a soft signal on Mail.ru; non-participating senders accumulate complaints invisibly.
- All CIS providers dislike auto-translate/low-content-quality mail more than Gmail does.
What the report shows per provider
- Inbox vs Spam folder placement.
- Auth (SPF/DKIM/DMARC) as seen by each provider — alignment differs.
- Provider-specific diagnostics (e.g., Mail.ru FBL readiness).
- Per-seed detail for regional variation.
Run a free test. CIS providers pre-selected alongside Gmail and Outlook. No signup.