How Do I Cancel My GMX Account?
GMX is a free email service similar to Yahoo! Mail or Gmail. GMX makes it easy to delete your email account if you no longer wish to use it; however, all of your personal information, including your contacts and emails, will disappear forever. GMX recommends making sure you want to delete your account before going through with the process.
Sign in to your GMX email account. Click "Settings" on the top navigation bar.
Click on the "My Account" tab. Click on "Account Details."
Click on "Delete Your Account Now."
Choose a reason for deleting your account, type your password, and then click "Delete Account." The system will delete your account and log you out of GMX automatically.