I simple don't find where a anonymous user can unsubscribe the membership.
I didn't find any menu hooks or anything like that. What's the correct way to handle this?
I'm also interested in knowing whether this is possible?
Since we have no way of knowing and verifying the identity of an anonymous user, they can't unsubscribe using the module.
A way of unsubscribing an anonymous user is to request their email in an unsubscribe form. Many newsletter systems are using this way. Also Newsletter module (http://drupal.org/project/newsletter) is using a similar way.
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