Gmail has a solid feature “Priority Inbox”. Priority inbox is an email filter, it filters important emails. It is not 100% automatic but it is very useful you can make it automatic only once you have to work for it. It shorts email automatically. It makes sections so you can keep your emails organized. Its most powerful feature is prediction, it predicts important emails.
It is very easy to understand, see below screen shot, you will see in Gmail inbox in top right side, to enable this feature click on that red bold link.
After enabling this feature, it will so you some emails as important and some as not important, this is what you have to do. Important message is marked yellow marker, if you think that message is not important you can click on minus sign. If you think a message is important you can click on plus sign.
It is not useful if you get only important emails but if you get daily many emails and some of them are important and others not, priority inbox will easily filter them. In your inbox you will see important emails first.