Sign-in seals are a safeguard from Yahoo! Mail. They help you fight online phishing scams (people trying to trick you into giving up your password or personal information by spoofing legitimate web sites).
Here’s how your sign-in seal works: You provide us with an image (such as a personal photo) or a secret message. Whenever we ask you to sign into Yahoo! Mail, we’ll display your image or message. If it’s not displayed, you may have landed on a “spoofed” site. It only takes a minute to create your sign-in seal.
Note: Your sign-in seal is saved on the computer that you create it on, not on Yahoo! Mail’s servers. So if you use more than one computer or browser, you’ll want to create a sign-in seal for each one. Also, don’t create a sign-in seal on a computer you share with strangers, such as those in libraries, Internet cafés, and other public places
Avoiding phishing scams is tough. Phishers know every trick in the book, and they’re dreaming up new ones as we speak. So here are some things to keep in mind while you’re online:
Don’t believe every warning you read—especially pop-up warnings that appear while you’re surfing the Web. Unscrupulous companies use pop-up ads to display false warnings about your computer. Ignore them.
Do NOT click any button in these pop-ups, such as a “Close” or “No” button, or the “Close” box that may appear in the upper-right corner of the pop-up. Doing this might install a virus or other malicious software on your computer. To safely close a pop-up ad, press Ctrl-W (if you’re using a Windows computer) or Command-W (on a Mac computer).
Be suspicious of “free” advice.You may receive an email that claims to be from a computer expert, warning you of a virus. These are usually hoaxes. Do not follow the steps described in any email unless you’re sure the threat is real.
There is no Yahoo! Lottery. Don’t be fooled by people pretending to be Yahoo! and offering cash prizes. We would never send you information about a contest you never entered. If you’ve received a message like “Final Notification: Yahoo! Mail Winner!” or “Your Email Address Has Won $XX million,” it’s a scam. Don’t reply to the email, don’t click any links in it, and never divulge any personal information. Instead, click the “Spam” button.
Phishing is the act of creating legitimate looking messages, masquerading as a trusted entity to lure you into clicking on emails that are designed to steal vital personal information like your password and financial data. To prevent such email forgery and spoofing we use DomainKeys Identified Mail (DKIM) which allows senders to digitally sign their emails so that Yahoo! Mail can then verify the authenticity of the sender. In addition, Yahoo! Mailsupports Domain-based Message Authentication, Reporting and Conformance (DMARC), a specification spearheaded by major technology providers and email senders to collectively fight spam and phishing scams.