Some think Apple Mail and Gail should play well together. But over the past week there has been a lot of chatter about the lack of proper support for Gmail in Apple Mail. David Sparks of Macsparky puts things into perspective:
The problem is Gmail is not IMAP. Neither is it POP. Gmail is something entirely … well … Google. While in the past people have been able to get Gmail working in Apple Mail it always involved copious amounts of scotch tape and chewing gum. Apple has never had any interest in building in support for things like Gmail labels and inbox filtering to Apple Mail. Why would they?
If you use Gmail, you should be using all of its features. Google has done some really useful things in their email sandbox over the years. You will never be able to use those features in Apple Mail. So my advice is to get over it and move on. Use the browser for your Gmail accounts or something like MailPlane, designed around Gmail.