in danger of beeing corrected by those who are responsible:
best practice should be that you ask support to change the email adress yourself after you sold the license.
because "deauthorisation" isnt possible.
”You may sell your copy of Max unless you purchased a teacher, student, educational institution copy or received the software as an NFR (Not For Resale). The sale will include all upgrades associated with the copy of Max you are selling. (It is highly recommended you also read the restriction details below.)
You must provide us with the full name and email address of the new owner. We will contact that owner and register your copy of Max in his or her name. At this time your authorization will be deactivated.”
but I do want to know where can I tell people to buy my license.