If you haven't heard the term "Inbox Zero" already, then you need to check out this web site.
I highly recommend you watch the video.
I have been using the inbox zero mentality for many years, but I didn't have a name for it so all I could do was brag that my inbox was empty.
In my life, I've seen some strange iterations of getting an e-mail inbox empty including one guy who printed all of his e-mail out, put it in piles (by category) on his desk, and deleted the messages. I'm not sure that is really getting your inbox to zero.
On the other end of the spectrum are those who have thousands of e-mails in their inbox and are making a futile attempt to manage their time with their inbox. All this system leads to is acting on the latest and loudest.
Running a zero balance on your inbox takes the discipline to set up. But it takes more discipline to use a system so you can generate trust in that system.
I use the GTD workflow. I have a copy posted next to my computer. See below.
There are two key steps that are easy to say, but hard to make yourself do.
1. As you read the e-mail, you have to answer the "Is it actionable?" question.
2. You have to have the discipline to implement the 2 minute rule.
If it is actionable (this includes my Someday/Maybe) AND it will take more than 2 minutes, then immediately forward the e-mail to your Evernote e-mail account, file that e-mail in the appropriate reference folder and go to the next e-mail.
If you do that one thing, then there are only two other scenarios.
1. It is not actionable, so it gets trashed or filed.
2. If it is actionable and it takes less than 2 minutes, then I immediately do it.
Even if you get a several dozen e-mails a day, you can quickly get through your inbox if you make yourself answer the "Is it Actionable?" question and then apply the 2 minute rule.
The bottom line is stop trying to do processing inside your e-mail inbox. ALL of my processing and project planning takes place in Evernote, not in Outlook or G-mail.