I like the idea of a native Linux email client. The UI looks pretty good too. It's really not hard to beat thunderbird.
Calling it version 1.0 is bullshit though. It's only about a month old: https://github.com/c9dev/penguin-mail/graphs/contributors?al...
A project with the complexity of an email client cannot be considered stable in a month. There are bugs that will only show up after a year. It has a calendar after all.