the best thing to deal with those issues is to forward the marketing messages still not being detected on your appliances. Personally I never recomment dictonaries or filters to block spam or marketing messages, simply because it takes performance and is less accurate, and more important, will cause false positives. The patters used in the antispam engine are way more complex and also look for such things like the context of a term or phrase, thus being way more efficient. Therefore, check out the knowledge base article about spam and marketing submissions, and also our latest blog post about the topic:
Article #471: How do I report Cisco IronPort Anti-Spam false positives or missed spam?