There is no Proton IMAP for hosted clients
Proton offers no IMAP or API access to third parties, by deliberate architecture and design choice - not a bug, not an oversight, and not something any client, including Curo, failed to build support for. Proton's whole model is built around keeping mail encrypted end-to-end and never exposing a plain IMAP interface that a cloud service could connect to.
Proton Bridge only works locally
The one way to get IMAP out of Proton at all is Proton Bridge, a desktop application you install and run on your own computer. It serves IMAP on 127.0.0.1 - localhost, meaning your own machine, and nowhere else. A cloud-based, hosted email client cannot reach that address, because it isn't reachable from outside your computer. This rules out every hosted client equally: Curo, Superhuman, Shortwave, and HEY all hit the exact same wall.
This isn't a Curo gap - it applies to everyone
If you've seen another product imply it can connect to Proton Mail directly, that claim doesn't hold up against how Proton is actually built. No hosted email client can present a genuine, direct connection to Proton Mail. Anyone claiming otherwise is either describing local-only Bridge usage or overstating what their product does.
The fix: sign in with Microsoft
- In your Proton Mail settings, set up a forwarding rule to send mail (or a copy) to a free @curomail.com address.
- Confirm the forwarding rule in Proton, following Proton's own verification step.
- Sign up for a free @curomail.com address in Curo if you don't already have one.
- Curo receives the forwarded mail natively and applies full AI triage, prioritization, and voice-matched drafting to it.
- Keep using Proton Mail as normal for encrypted storage and sending - nothing about your Proton account changes.