Dealing with spam is a tough situation, as spammers are constantly adapting their methods. All our servers use the latest spam filtering technology. However, our policy is not strict. While this does let some spam through, it is better than potentially blocking legitimate emails with overly zealous filtering settings.
The free and popular email client
Mozilla Thunderbird has a very good adaptive spam filter built-in, which allows you to choose how strict or lenient you want the filters to be and to fit them to your needs.