When you first use your GMX mailbox, your personal spam filter is still empty. Your personal spam filter is not trained until you click Spam or Not Spam to move incorrectly saved e-mails into the Spam folder or the Inbox folder. The same occurs if you move e-mails to the Spam folder or the Inbox folder by drag & drop or using the Move button. The spam filter remembers the following properties:
If you receive another e-mail from the same sender, or an e-mail with a similar text pattern from another sender, the e-mail is automatically saved in the appropriate folder.
To ensure that your personal spam filter functions perfectly, you have to move e-mails incorrectly saved as spam, and undetected spam mails to the correct folder. If certain e-mails are saved in the wrong folder repeatedly, you can reset the spam filter in the Spam Protection settings to solve this problem.
The text pattern component in your personal spam filter works with wordlists that are created from the e-mails you have selected as Spam or Not Spam. The filter determines the frequency with which words occur in the selected e-mails and creates a custom model for your mailbox. This model is used together with the probability methods to classify new e-mails as wanted or unwanted. Put simply: the more often a word occurs in wanted or unwanted e-mails, the more it is weighted during filtering.
Your whitelist is also processed before the spam entries in your personal spam filter. Example:
If you use POP3 to access your e-mail, you should set your e-mail client or your mail app to leave copies of the e-mails in the GMX mailbox. You can then log in at gmx.com and move incorrectly classified e-mails to the right folder using the web interface.
If you access your e-mails using IMAP, you can move incorrectly classified e-mails to the right folder directly in your e-mail client or your mail app. Your personal spam filter remembers the text pattern of the e-mail, but not the sender address. To train the spam filter optimally, you must log in at gmx.com and use the web interface to move the incorrectly classified e-mails to the right folder.