You can, of course, use your web browser on the Gmail site to check your mail. That will be useful if you ever have to use a Mac or PC in an Internet café, or a Mac that belongs to someone else for some reason.
It’s also useful if you’re a fan of the Google+ social site, as the Gmail web site allows you to catch up with your Hangout contacts and chat sessions on Google+, as well as just checking your email.
The email features provided in this web browser interface work pretty well, but many Mac users may still prefer to use the more familiar Apple Mail instead.
Email tips for Mac Mail