I'm guessing that, by now, you've done a deep dive into your email account settings. You know all the filtering and labeling tricks. But those email hacks usually just organize you. They don't do a ton to limit how many legitimate emails you get every day. For that, you have to lay some ground rules that have nothing to do with checking or unchecking a box.
1. Use chat.
I can't tell you how many times people have treated email like a chat program with me, emailing one question at a time or, sometimes, single words. The answer? Really use chat! Facebook, Skype, LinkedIn--any one of those lets you get the answers you need fast without cluttering your inbox. They also usually give you a way to download the conversation if need be, so you'll still have a record of what was said. If you can't chat for long, just say so.
2. Be (a lot) pickier about hitting reply.
Author Phil Simon swears by the 3-email rule, which basically says that, after you exchange three emails, you talk. This forces people to get to the point and encourages live one-on-one discussions for complicated issues. But you also can set yourself a quota--for example--no more than six replies a day--and stick to it. When you use this strategy, people eventually learn that they've got a better chance of communicating with you if they leave email behind.
3. Schedule email sessions.
People tend to give email whatever time they have available between other jobs. Draw clearer boundaries by scheduling email into your day with defined start and stop times. Again, you can only reply to so many emails within a particular session, so you naturally limit the number of replies that are going to hit you later. It also sends a message to recipients about when you're actually available to read and respond. Once you've decided when your sessions will be, set up an auto reply for when you can't answer.
4. Heavily encourage notes.
Many times, emails are exchanged for clarification. If people are taking good notes when they talk to you, be it through pen and paper or digital recordings, they can reference those and give you back your time.
5. Reply at the end of the day.
If it works for your schedule, read--and read only--your email earlier in the day, handling anything urgent by phone or in person. Then reply to what's left in the evening if you can. This way, you avoid playing email tag and "inbox growback", as it's not as likely people will respond until the next day. You also have a better chance to really think about your response so that it's concise and clear, both of which encourage fewer additional replies to you.
6. Look at your attitude and open your door.
People sometimes email team members and bosses because their recipient simply isn't friendly enough in person. They feel like it's safer to communicate in writing than face-to-face. This doesn't mean the recipient purposely is being a jerk--they might not even realize they're creating a wall. But take a hard, honest look at how others interact with you. Ask for feedback. Make sure both your behavior and your words convey openness, and have a time of day designated for people to come talk to you with needs and concerns.
7. Make other communication methods easier to use.
People are more likely to use an alternative form of communication if they know you endorse it. Put links to your LinkedIn, Twitter or Facebook profiles in your email signature for example, or put those links ahead of your email on your contact page. State your communication preference wherever you can!
You might have some messages others easily can handle for you. If you don't like the idea of an auto-reply, consider offering account privileges so someone else can help you out when you're away.
9. State your email policy.
Considering the above, put your email policy as a footer in your email signature. If people keep emailing you unnecessarily or wonder why you don't reply, you politely can inform them that your policy is clearly indicated at the bottom of every email you send.
Good business leaders, we are told, are finishers. They get the job done. But the trouble is, you can never really "finish" email. There's always one more. You have to get past the psychological idea that a lack of a zero inbox somehow equates to incompetency and failure if you want to free yourself to do greater things. Once you acknowledge that and let yourself be "OK" with a few straggler messages, the above points are a snap to integrate.