Mailspring looks nice. I would like the metadata to be under my control and not synced to their servers. The fact that I need to login to their machines turns m

Mailspring looks nice. I would like the metadata to be under my control and not synced to their servers. The fact that I need to login to their machines turns me off. I'm open to running my own instance of their server. I do not like requiring "the cloud" to use my email client.