Nylas Mail Basic does NOT store your mail data in the cloud. It still uses a cloud service for some features (like read receipts), but all the data is local on your disk and auth credentials stored in your native OS keychain.
Nylas Pro currently syncs in the cloud to enable some of the pro features not currently offered in Nylas Mail Basic and to provide a much easier to use modern API wrapper around mail data. The cloud syncing infrastructure is open source and you can run it yourself and inspect the code.
All editions (both Basic and Pro) need a Nylas ID. This lets us manage subscriptions for those who want to upgrade. The code is open source on GitHub (nylas/N1). You can fork & run yourself without a Nylas ID. You just won't get any cloud-enabled features.
We never send mail, contact, or calendar data to 3rd parties. We do, however, use 3rd parties for basic usage and performance statistics and self-host as much reporting infrastructure (like Sentry) as possible.
Nylas Pro currently syncs in the cloud to enable some of the pro features not currently offered in Nylas Mail Basic and to provide a much easier to use modern API wrapper around mail data. The cloud syncing infrastructure is open source and you can run it yourself and inspect the code.
All editions (both Basic and Pro) need a Nylas ID. This lets us manage subscriptions for those who want to upgrade. The code is open source on GitHub (nylas/N1). You can fork & run yourself without a Nylas ID. You just won't get any cloud-enabled features.
We never send mail, contact, or calendar data to 3rd parties. We do, however, use 3rd parties for basic usage and performance statistics and self-host as much reporting infrastructure (like Sentry) as possible.
(I build Nylas Mail)