Mailplane supports multiple Gmail and Google Apps accounts; the app allows you to easily switch between accounts without the need to sign in/sign out from the Gmail accounts.
With full iLife integration, you can also browse and attach files from your iPhoto and iTunes libraries too. Downloads can be directly imported into iPhoto as well. The integrated screenshot tool lets you capture and attach a window, screen or region.
You can Drag and Drop files and images on the dock application icon, or any Mailplane window to create and upload attachments. And with automatic photo optimization, image attachments can be converted and resized to make the message even smaller.
Mailplane can play a user defined sound, as well as show the number of unread messages in the application icon, account drawer and status menu item. As Mailplane monitors all Gmail accounts, unread message counters and message subjects are displayed for each account. More...