3 steps to solve your email overload problem?
Solve your decision problem first.
Most likely, you don't have too much email, but rather you have a problem deciding what and how to do with your email.
Here is how you could deal with this:
1) Automate most commonly requested emails, and even consider putting a disclaimer on what you will and will not talk about via email.
Put processes in place for your email workflows.
If you get emails that always require a certain type of response, or a follow up, make sure that those processes kick off on their own, without requiring you to participate in the email flow.
Filter anything you don't want to read, and auto-trash useless emails, like out-of-office replies.
2) Use tools like text-expander to fill in auto-responses to common issues. This way you can still sound human, and appear like you are responding with a personal message, while in reality doing almost no work to respond.
3) Set a time for when you processes email, and do not touch your emails in any other time. Also, Do not put aside email that you actually want to respond to. You will never get back to them, so either respond right away, or forget.