Link: stop spam from foreign countries in Outlook (Lifehacker.com)
It's known that most spam (particularly malware such as keyloggers) originates overseas (Estonia, Moldavia, China, Poland, etc.) By blocking email from most of the undeveloped world, I've successfully reduced spam by 95 percent in the past year. In Outlook, click Actions > Junk E-Mail > Junk E-Mail Options. Click the International tab, then the Blocked Top-Level Domain List button. Now select the countries you wish to block.
Killer solution! Before I hooked up with SpamArrest, the foreign e-mails used to drive me nuts. This filtering takes about 30 seconds to complete and should keep a ton of unwanted gunk out of your inbox. Care to share your favorite anti-spam solution? You know where: the comments!