Although my anti-spam set up works fairly well, I had been surprised in the past months (apparently starting end of May) to get some obvious spams (involving e.g. ‘Valium’ in the subject) going through it without problems. Only today have I realized that this was because the mails were not checked by my SpamAssassin, but (supposingly) by a SpamAssassin on popular free Web-based email services (e.g. yahoo or hotmail); that is, they included the following headers:
X-Spam-Checker-Version: SpamAssassin 2.60-spambr_20030926a on popular_mail_service.com X-Spam-Level: X-Spam-Status: No, hits=-5.9 required=5.0 tests=AWL,NO_REAL_NAME autolearn=no version=2.60-spambr_20030926a
Due to the way my SpamAssassin set up works, they were not re-checked when entering my spam filters!