Something, that you should also be aware of with the email to case functionality, is creating validation rules to prohibit the creation of cases when meet certain criteria that would be considered spam. as it can become out of hand very quickly with auto-reply loops amongst other things.
@@BenTampa AND( ISNEW(), OR( CONTAINS(LOWER(Subject),"WhoisProtection - Your email has been received"), CONTAINS(LOWER(Subject),"your message has been received"), CONTAINS(LOWER(Subject),"Your request has been logged"), CONTAINS(LOWER(Subject),"Your Ticket has been logged") ) ) as an example formula that can be used to validate a case prior to creation and block spam cases. this can be expanded to include supplied email, or parts of supplied email.
