How to Control Web Beacon and HTML Form Filtering for Outlook Web Access
Web beacon is a file object, such as a transparent graphic or an image that is put on a Web site or in an e-mail message.
Web beacons are typically used together with HTML cookies to monitor user behavior on a Web site or to validate a recipient’s e-mail address when an e-mail message that contains a Web beacon is opened.
Web beacons and HTML forms can also contain harmful code and can be used to circumvent e-mail filters.
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Ex-Shell 