I deleted the thread after freezing it for a day. It was becoming too XOC'ish.
Try going into your AF Profile and see if the thread is listed under your "subscribed threads". If so, remove it and that should end the e-mails.
As a side note I created a folder on my home e-mail to redirect any AF message notifications. Sometimes I want to know if someone responded, nonetheless they get redirected out of my normal e-mail.