Gmail has always done a pretty good job of making sure you never see spam. This helps cut down on the amount of email clutter we have to deal with, but this isn’t the whole picture. While Gmail offers an extensive filtering system to help you achieve the coveted “Inbox Zero,” you still have to know what you’re doing. It can also be a tedious process.
Priority Inbox aims to help you with that. Rather than manually going through your emails and trying to categorize what should go where and what is important, Priority Inbox does it for you based on your habits.
Gmail has always been pretty good at filtering junk mail into the “spam” folder. But today, in addition to spam, people get a lot of mail that isn’t outright junk but isn’t very important—bologna, or “bacn.” So we’ve evolved Gmail’s filter to address this problem and extended it to not only classify outright spam, but also to help users separate this “bologna” from the important stuff. In a way, Priority Inbox is like your personal assistant, helping you focus on the messages that matter without requiring you to set up complex rules.
The way it works is simple. Your inbox will now be broken down into three separate sections:
- Important and Unread – these are messages that are important to you and you have not read them yet. If you see anything in this section that is actually not important, you can click a button to remove it. Gmail learns from the changes you make.
- Starred – these are messages you manually starred. They may or may not be important, but you have decided you want to keep them visible.
- Everything Else – just as the name states, this is all the other “stuff” that is hitting your Inbox. As you move through this section, you can click a button to star or mark something as important. Again, Gmail learns from the changes you make.
As messages come in, Gmail automatically flags some of them as important. Gmail uses a variety of signals to predict which messages are important, including the people you email most (if you email Bob a lot, a message from Bob is probably important) and which messages you open and reply to (these are likely more important than the ones you skip over). As you use Gmail, it will become better at categorizing messages for you. Users can help it learn by clicking the 
or 
buttons at the top of the inbox to correctly mark a conversation as important or not important. (You can even set up filters to always mark certain things important or unimportant, or rearrange and customize the three inbox sections.)
Priority Inbox will be rolling out over the next week to everyone, including Google Apps users. When it’s activated for your account, you will see a red link saying “New! Priority Inbox” in the top right of your Gmail. You can also check to see if you have a new “Priority Inbox” tab in your settings.
via Email overload? Try Priority Inbox – Official Gmail Blog