It always happen that in your mail box you receive lots of unwanted mails and sometime due those unwanted mails you lose your important mail.
Sometime due to those hundreds of unwanted mails you may miss your Boss’s mail which can be disaster for you.
Priority Inbox (in beta)—an experimental new way of taking on information overload in Gmail.
Gmail has a 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.
Priority Inbox splits your inbox into three sections: “Important and unread,” “Starred” and “Everything else”.
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). And as you use Gmail, it will get better at categorizing messages for you.
Priority Inbox will be rolling out to all Gmail users, including those of you who use Google Apps, over the next week or so. Once you see the "New! Priority Inbox" link in the top right corner of your Gmail account (or the new Priority Inbox tab in Gmail Settings), take a look.