We changed the behavior of the unsubscribe merge tag to obfuscate the email address of the person who clicked the link. Instead of showing the entire address, the md_email parameter now displays the address as something like x****@x***.*** .

Previously, if a customer clicked an unsubscribe link, their email address was displayed on the Unsubscribe page in full. By obfuscating the email address, this change provides better security.