Already suggested (with more votes): http://feedback.airmailapp.com/forums/274948-airmail-mac-3-x/suggestions/7765770-upgrade-your-adressbook
Admin should merge these.
This already exists: http://docs.airmailapp.com/airmail-for-mac/integrations/calendar-events-airmail-for-macos (and also for Fantastical: http://docs.airmailapp.com/airmail-for-mac/integrations/fantastical-airmail-for-macos)
Please DO NOT try to duplicate calendar functionality, like you do with Contacts (but shouldn't).
dealbreaker, along with not supporting flags or offline use. bye Airmail :-(
This issue and lack of flags make the $15 investment (Mac & iOS) worthless. I guess I just assumed since mail clients have been doing this for like, 30 YEARS.