Mailspring-Sync VS Mailspring-Libre

I was hopeful that https://www.nylas.com/ would be the de-facto "adapter" placing a common API surface on top of the major providers and dragging them into a modern-API world. They even had an email client of their own as a proof of concept (forked by one of the original authors as https://github.com/Foundry376/Mailspring - and its reusable core https://github.com/Foundry376/Mailspring-Sync may be interesting to many here). But they've pivoted towards making their API only available behind B2B contracts and opaque pricing, and primarily used for corporate email monitoring and CRM use cases - perhaps because security and privacy considerations are nontrivial. I'm still rooting for them but it's a shadow of what it could have been.

MailSpring is either done to look at soon ... it's either very close to finalizing Bridge support or in fact done. It's not clear to me, there's a discussion in GitHub. Nice thing about MailSpring is that it has a Linux client (Postbox only has Mac and Windows).

Yeah that's what I found too.

If you want to give it a try I recommend you to use libre version since the telemetry has been removed in that one: https://github.com/notpushkin/Mailspring-Libre

Seconding the Mailspring recommendation, but be aware that it requires a Mailspring ID. There’s some progress, though, with a telemetry-free fork[1] (that’s the version I’m using right now) and plans to make the ID optional in the official client [2].

[1]: https://github.com/notpushkin/Mailspring-Libre

[2]: https://community.getmailspring.com/t/mailspring-without-mai...

N. B. Please note that Mailspring Libre build isn't fully open source right now: the sync engine, MailSync, is proprietary, and while we're working on replacing it, it probably won't happen anytime soon. By downloading Mailspring Libre build, you accept the MailSync license (which doesn't affect you as a regular user).

I've just started using Mailspring-Libre. I've only used it for basic scenarios so far but I have no complaints. I can't speak for power-user features yet.