The plugin already added unsubscribe link added to the email send by activity notification emails, message notification emails, group notification emails.
Any user can unsubscribe email notification by one click only.
Shotcode ::
[az_unsubscribe_emails]
[az_unsubscribe_emails user_id=100]
-- You may use the shortcode with user id for specific user to give unsubscribe link.
-- If you not passing user id, it will return the current login user's unsubscribe link.
-- The shortcode just return the full url of unsubscribe link and you may use your way in your html.
-- If no user login then it will process automaticaly, redirected to login page and unsubscribe page....
User ID wordpress filter ::
azbp_unsubscribe_user_id
-- You can user the filder for change user id for unsubscribe.
User Subscribe/Unsubscribe Links::
http://YOUR-SITE-URL.COM/members/USERNAME/settings/notifications/?az_unsubscribe=all
http://YOUR-SITE-URL.COM/members/USERNAME/settings/notifications/?az_subscribe=all
OR
Default Links
http://YOUR-SITE-URL.COM/?az_unsubscribe=all