Email users create accounts expecting a modicum of privacy and security. Though that's great for adults making privileged or intimate communications, it presents a challenge when you want to monitor your child's Internet usage. The variety of ways to use email means there's no one set method for finding a secret email account. The best technique is to work through the different possibilities until you find what you're looking for.
Open your regular email page, such as Google or Yahoo! mail. Click on the email address field and look at the auto complete options that appear. If one is unfamiliar, it may be a secretly created email account.
Check your browser history for sites that offer free email. In most cases, the listing will include both the web address and the email name used with that account.
Scan deleted files in your child's regular email address. Nearly all free email accounts send a confirmation notice to a previous email as part of the creation process. Though most kids will be smart enough to remove that mail from an inbox, permanently deleting an email usually requires extra steps that your child might not know about, or might not have bothered to complete.
Check social media accounts your child uses or owns. They might include mention of email addresses you don't know about.
Look at the email settings on your child's phone. If he has a secret email address, he might have set it up to receive messages on a more personal mobile device.
Install a key logger program on the family computers. These programs monitor what happens on the computer. They will tell you what sites your child visits and what keystrokes she uses while there.
These are all ways to find out covertly what your child is up to on the Internet. The best practice is to maintain an open, honest relationship with your child where she feels comfortable using only the email addresses you know about.
Though you have the right to take these actions with your own minor child, this kind of snooping on an adult child is often illegal. It's usually against the law to install a key logger on a computer you don't own.