This page aggregates measured, corroborated evidence: donors' iPhones recorded apps contacting this domain, every claim below was reported by separate accepted donations and published under a human verdict (later rows for an approved app inherit its verdict). A contact is a measurement, not an accusation — it does not show what data was sent.
api.protonmail.ch
classified as first-party · 2
What our research panel found AI-drafted · human-reviewed
We ask several independent AI models the same question and publish their answers separately — cross-vendor agreement is evidence against fabrication, and disagreement is worth seeing. 3 of 3 models answered, overall confidence high. A human reviewed this domain's claims before anything here published.
Anthropic Claude — first-party
api.protonmail.ch is the Proton Mail service's own API endpoint, matching the app's publisher and core email functionality, so it is a first-party contact. The app's label already declares collecting account and diagnostic data, which covers this flow; no third-party sharing is implied.
OpenAI — first-party
api.protonmail.ch appears to be Proton Mail's own API domain based on the app's Proton Mail identity. A first-party service contact is not by itself evidence of a data flow outside the declared privacy label.
Google Gemini — first-party
The domain api.protonmail.ch is the official first-party backend API for Proton Mail used for core app operations. First-party communication with the app's own domain is expected and does not represent undisclosed third-party sharing.
Apps measured contacting this domain
| App | Label gap | Donations | Contacts | Seen |
|---|---|---|---|---|
| Proton Mail: Encrypted Email | — | 3 | 456 | 2026-07-30 |
The corpus grows one report at a time: donate your App Privacy Report — anonymous by design.
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