Despite the proliferation of other communications methods, email remains the defining application of the Internet age -- and a huge source of frustration when you feel like you've got more messages than you can cope with. Here's some time-honoured tactics for trying to clean out an inbox that's overloaded with unread emails.
Firstly, an important point: there is no one absolute failsafe method for either getting your inbox cleaned out or making sure it stays that way. Why? Because people are different, and hence different organisational methods will appeal (and will have more chance of sticking for more than a day or two). So this isn't a prescriptive guide: it's pointers to some issues and tactics you might consider when you're faced with a scary unread count. (Again, that's subjective: some people feel swamped if they've got 10 unread messages, others can happily have 1000 and feel quite unstressed.)
Do I need to do anything?
Sometimes, you have no choice about whether to kick in with email spring cleaning. If you work for a company with an enforced mailbox size limit, then regular pruning is going to be essential. But sometimes you feel bad about not having a clean inbox simply because, well, it seems messy.
Users of Web-based services like Gmail often argue that this is an outdated approach: you should be able to store as much mail as you want, confident that you can use search functions to dig it up. If you're happy with that approach (and your inbox isn't nearing capacity), then there may not be any reason to clean out old email. Indeed, taken to its extreme, there might not even be any need to use labels or folders if you're confident you can find what you want through searching.
Bear in mind, though, that being able to store so much mail can actually make it harder to keep on top of what you've actually dealt with, so you might want to give some thought to the issues raised under 'Work out a response strategy' below. Equally, if you are happy with deleting mail that's no longer relevant, don't feel pressured into keeping it just because there's theoretically space to do so.
Filter in intelligent ways
Assuming you do need to work through an overflowing inbox and delete or archive some items, then the first useful strategy is often to look at your mail glut in a different way. Most mail clients show email sorted by date. This in itself can be useful if you want to do some mass deletion (let's face it, if you didn't respond to something a year ago, the odds of it being helpful to do so now are pretty short).
However, you can often work through mail faster by switching to an alternate view. My own preferred inbox-blasting method is to sort by sender: that lets me ditch entire sequences of irrelevant mail (like older newsletters) quickly, as well as quickly moving all messages to relevant folders. If you're facing a corporate inbox restriction, then sorting by size can help you get rid of the messages carrying ludicrously large PowerPoint files.
If you're serious about cleanup, resist the urge to reply to any email you encounter during the cleanup process, no matter how urgent it sounds. Mark it as needing a reply (using whatever method seems suitable for your preferred client -- you could add a label or flag, or place it in a special folder, or just leave it in your inbox), and deal with that in a separate session.
Use automation for better processing
Whether on your PC or online, modern email clients have plenty of intelligence built in, including rules to automatically categorise incoming mail, the ability to distinguish group emails from individual ones, and the ever-popular conversation view that groups emails into related threads. Making good use of these can help ensure your inbox doesn't overflow. Our list of the top 10 email productivity boosters has more details on some handy approaches in this field.
Work out a response strategy
If you don't want to do regular email logjam clearing, you need to get more efficient in how you handle the incoming flow. Again, this is often a matter of personality and job requirements. Some people prefer to set specified times of day for dealing with email: others have a one-touch approach, where email is decisively dealt with as it arrives. If you feel swamped by long emails, learn how to strip them down to their essentials to write faster replies. Other approaches you might want to consider include skipping the traditional "out of office" message and taking an email sabbatical.
Work out why you get so much email
One obvious but often neglected step to dealing with email overload is stopping email you don't want from arriving in the first place. It's all too easy to end up with a bunch of newsletters you don't want -- if you're routinely deleting those kinds of messages without reading them, then it's time to unsubscribe. Another good option is to separate email sent uniquely to you from email you're just copied on -- you can't necessarily always ignore the latter, but you can give it lower priority.
What techniques do you use to keep email under control? Share your wisdom in the comments.
Lifehacker 101 is a weekly feature covering fundamental techniques that Lifehacker constantly refers to, explaining them step-by-step. Hey, we were all newbies once, right?