how do i unsubscribe automatically?

[420]

when i use the admin control panel to send out a newsletter to my members, how do i allow them to automatically unsubscribe from the email blasts, by clicking on a link at bottom of the newsletter?
without deleting their threads or deleting their account.

a simple feature to turn their profile settings from Receive Emails from Administrators to NOT Receive Emails from Administrators.

thanks