Block Countries:
Effectiveness: Medium-High
Advantages: Will block messages from countries that you do not exchange email with. For instance, if you do not exchange email with anyone from China, it may be beneficial to block messages that originate in China, since these would most likely only come from spammers in your particular case.
Limitations: Can be inaccurate in some circumstances if a site you deal with has their mail server in a different country.
Recommendations: We recommend enabling this for most users.
