Airmail for Mac was just updated to version 1.0.4 and brings with it lots of new features, improvements to existing ones, and bug fixes. Most notably, Airmail now has Google Drive support and also allows both Droplr and CloudApp support for attachments in addition to Dropbox. You can also now choose to delay sending an email if you'd like.
I've been using Airmail now for about a month and I've been really impressed with the way it handles accounts and how quick it is. If you're a current user and you've been experiencing a few crashes here and there, you'll definitely want to grab the update as it may address certain crashes and bugs users have been experiencing.
There's also a long list of new shortcuts and preferences included in the update. Hit the link below to grab the update and view all the changes in this version.