Thanks for releasing this. I've been looking for a Mailplane alternative for a while, ever since Gmail started becoming a resource hog when they forced everyone onto their new interface. Is there a chance you could recompile this to support 10.14? I'll most likely not be upgrading from Mojave for the foreseeable future, until my 2013 MacBook Pro stops working and I'm forced to get something new.
Sadly, no. Mimestream already uses SwiftUI for parts of the UI, and SwiftUI requires Catalina. I plan to release an iOS/iPadOS version in the future, so Mimestream will be investing even more heavily into SwiftUI. At some point later this year, Big Sur will become a requirement, too. I sympathize with those that remain on Mojave, especially those who need to run 32-bit apps, but as a 1-man project, it seemed like a n…
One thing I don't like though is the Big Sur requirement as early as this year. I'm also still on Mojave and will probably upgrade to Catalina in the coming weeks.