MyMac Magazine: Mailplane gets 4.5 out of 5
Mailplane has changed my entire mindset about email. I no longer deal with sync issues between computers. I no longer worry about managing local copies of everything. If you can wrap your brain around having your email in the cloud, or even if you just have a few Gmail accounts you want to manage in addition to some other email accounts that you do deal with through a regular email client, Mailplane makes things smooth and easy for you, just like using a regular email client. I recommend it to any heavy Gmail user on the Mac.