Still a bit buggy but I love it!

Most of the shortcuts don’t work or sometimes stop working.
Especially, I can’t archive with ⌘← and it’s very very frustrating.
Also, spacebar just opens the message in a new window, but it should scroll down on the message.
Filter rule is not flexible: especially I cannot forward mails by rule, and it’s really needed!
(Forwarding emails by AppleScript doesnt work at all.)

The snooze function works well and it’s definitely the best alternative to Mailbox.app!

mitsukif about Airmail - Lightning Fast Email, v2.6.1