Hi
Because you are using our Free Thumbshots plan, part of this service is providng an email alert when the Thumbshots hits run out. We are not able to unsubscribe this unless if you Terminate the plan all together.
the alternative is to set up a Filter on your email service to move them to a different folder. Here are some tutorials.
http://help.yahoo.com/tutorials/mmail/mmail/mm_filter1.html
http://support.google.com/mail/answer/6579?hl=en