Does Mailspring sync my email through a third-party server?

That Mailspring ID has me wondering: does my email ever get seen by your servers?

No! Mailspring connects directly to your email provider’s IMAP and SMTP servers. Mailspring stores your email credentials securely in your system keychain or keyring, and does not send your email login information to any third parties, including our own servers. Mailspring fully supports VPNs and is compatible with workplace environments that require you not to share your email password with third parties.

In the future, we may add features that rely on having your email credentials in the cloud, such as cloud-based mail rules, snoozing or “send later”. If and when these features are added, they will always be opt-in, and Mailspring will explicitly ask for your permission before sending your email passwords anywhere.

See also: Mailspring Data Collection

Would be nice if there was an option for Mailspring to behave like Mailpile, in that emails are downloaded to the device, deleted from the server, with p2p sync between devices.

https://www.mailpile.is/faq/#wha-2

Perhaps as one of the todos on: