This story is part of Try This, CNET's collection of simple tips to improve your life, fast.

I used to be surprised at what contents would arrive in my mailbox on a daily basis. Some days it would be a load of junk mail, a letter from an old friend or an important financial document. But now I know exactly what's coming before it ever lands in my mailbox.

To separate the wheat from the chaff and get alerts on important incoming mail, I signed up for Informed Delivery. It's a free feature from the US Postal Service that sends me digital previews of my mail before it arrives, letting me know what's coming and when. Informed Delivery is available to almost all residential Postal Service customers.

If you're hoping to thwart porch pirates from stealing checks or simply want a clue about what's coming in the mail, read on to learn how Informed Delivery works and how you can sign up. For more tips, here's how to bake a cake without a pan and how to fall asleep with a 5-minute routine.

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What is USPS Informed Delivery?

Informed Delivery is a free mail-tracking service from the USPS. It uses the scans of your incoming letters to provide previews in a daily email and in a personalized online dashboard on USPS.com or its mobile app. The dedicated Informed Delivery mobile apps have been discontinued, but the service works within the official USPS Mobile app on iOS or Android.

When the post office processes mail with its automated sorting equipment, it creates a digital image of every letter-size piece of mail. Users of Informed Delivery get access to that info via notifications when each piece of mail to your address is on the way. 

As part of the program, you'll get an email every morning, Monday through Sunday, with digital previews of your incoming mail. You'll also see a black-and-white image of the front of the envelopes. It's important to note that for those who share an address or mailbox, you'll see all letters to everyone at the address -- there's no way to separate mail by recipient.

Who can and can't use Informed Delivery?

Informed Delivery has some limitations. For example, it will work with many residential and personal post office box addresses -- but not businesses. It also won't work for some residential buildings where USPS hasn't yet identified each unit.

How do I sign up for Informed Delivery? 

If you've decided that you want previews of your mail each day, visit the Postal Service's Informed Delivery page. The sign-up process will create an online USPS account if you don't already have one.

1. Click Sign Up for Free.
2. Enter your mailing address to confirm Informed Delivery is available for you. If it is, accept the terms and conditions and click Continue. 
3. Choose a username, password and security questions. Enter your contact information and click Continue.
4. Now you'll need to verify your identity. You can do it three ways: Select Verify identity online to receive a verification code on your phone. Click Request invitation code by mail if you want USPS to mail you a code. You can also visit a post office to verify your identity in person.

Voila: You're registered for USPS Informed Delivery. It may take up to three days for your account to be activated and for you to start receiving previews of your mail. 

Be aware that signing up means you'll see all mail that's scanned by the post office and heading to your address. You can cancel the service at any time.

Which mail isn't tracked by Informed Delivery?

USPS does not take digital images of catalogs or magazines. If one of those items is arriving, you'll receive a message that says, "A mailpiece for which we do not currently have an image is included in today's mail."

And while you can track the delivery status of your packages and their expected arrival time, the Postal Service doesn't capture images of packages. However, Informed Delivery does let you create an electronic signature for authorizing package delivery when you're not at home.

For more tips, here's how to wash your car without water, how to start a fire with Doritos and how to avoid avocado hand.