I have nearly 21,000 email messages in my inbox. I don't file, archive, or delete anything.

Think this hands-off approach is a bloody mess? Personally, I think my approach is working--I try to touch email messages as few times as possible, spend zero time organizing them and feel confident if I ever need to search for a keyword or for someone who works at a particular company, Gmail's search capabilities can find it in my massive pile.

Yet I'm doing it all wrong, according to email-filtering service Sanebox, which advises the opposite strategy--one in which you let its algorithms sift through all your messages and organize them neatly into manageable folders that do all sorts of neat tricks. I've tried it, and it is, indeed, slick.

In fact, the folks at Sanebox argue that keeping all your mail in your inbox is "terrible for your productivity," the company opined in a really helpful (and entertaining) list of 100 email hacks it recently compiled.

Here's a roundup of the company's best tips.

Turn off notifications.

You're humming along with work swimmingly and you hear it--the ping on your phone that tells you an email just landed in your inbox. Now you're curious, so you hop in there to see whom it's from and your productivity just stopped dead still. Unless you're waiting for some time-sensitive critical message, don't give yourself an excuse to keep checking email. Silence notifications wherever you're getting them (including visual pop-ups on the desktop). A better bet is to set aside a few times during the day to deal with email.

Never unsubscribe from suspicious emails.

Hate spam? One way to get even more of it is to hit an Unsubscribe link in a message you're not sure why you're getting. If you do, you could end up at a website where you're asked to input your email address to confirm your desire to unsubscribe. Now the spammer has verified your email address (it was only a guess that landed the original message in your inbox) and can sell it to others who will barrage you with messages.

Don't use images in your signature.

Sometimes people are looking for a particular file and filter their messages according to which ones include attachments. By including an image (which becomes an attachment) in your signature, you're actually mucking up their search results. Plus, tossing around unnecessary graphics is a waste of bandwidth.

Don't use email to discuss a difficult subject.

If someone at work needs straightening out, don't do it on email, particularly if there's a chance the discussion could become contentious or if someone could be hurt or offended. It's much easier to gauge someone's emotions and respond appropriately on the phone, via video chat, or even better, in person.

Never email your credit card information.

Unencrypted email is not secure, so you don't want to use it to communicate any kind of confidential information. For one thing, a message may have to cross any number of networks before a recipient gets it, and once it arrives, how will that person store it? What if his or her system is compromised?

Forget about attachments and use links instead.

Dropbox, Google Drive, Microsoft SkyDrive, and the like are great because you can share a file with others and as soon as someone makes an edit to it, the change is viewable by everyone who has access. Attachments, on the other hand, are static--if you find yourself in an email volley including various iterations of the same document, things can get confusing. With a URL linking to the cloud, however, version control isn't a worry.

Stop scanning and faxing.

If you've ever been emailed a contract to physically sign and return to someone, you know what a pain this can be. You either have to print it out and find an actual fax machine or take the time to scan, save, and attach each page into an email.

Instead, use an online fax service such as Hello Fax. The first five pages are free; after that, plans start at $10 a month.

Amp your network right inside email.

Rapportive is a free tool for Gmail users that adds a sidebar to each message you receive that shows you what the person looks like, information about what he or she does, where he or she is located, as well as what social networks he or she uses. The best part is this: Directly within the window, you can send a LinkedIn connection invitation, add someone to a Google+ circle, follow him or her on Twitter, or friend him or her on Facebook.

Fill in the recipient last.

There's nothing worse than accidentally sending a message before you intend to. Save yourself this embarrassment by leaving the "To" field empty until your missive is perfect. Gmail users can also use Google's Undo Send feature, which gives you a few seconds after you hit Send to change your mind. To turn it on, go to Settings (the cog on the right of your Gmail window), then Labs, where you'll find the feature plus a slew of others you might find helpful.

Use an unguessable password that's different for each account.

You've heard this one before, but it bears repeating because lots of people still get in trouble for not heeding this advice. Your email password absolutely has to be one that someone can't guess and one that you don't use with any other account.

To ensure it can't be guessed, use the first letters of a memorable phrase, such as yamsmosymmhwsag, a 15-character password (longer is better) taken from "You are my sunshine, my only sunshine. You make me happy when skies are gray."

Another trick: Think of a two-word phrase at least eight characters long that you can remember, such as "SteakBurrito" and pepper it with symbols that look like letters, like this: St3@kBurr!t0. Then, for each site for which you need a unique password, take the first and fourth letter of the site and stick it in the middle of your skeleton key. So, for Facebook, your password would be St3@kfeBurr!t0.

And don't store all your various passwords on paper or in a file somewhere but in a password manager such as LastPass. Not only can the service generate unique passwords, it's free and available as a plug-in for all the major browsers.