Our good friends at Combined-Knowledge in the UK have published a nice white paper on how to configure SharePoint Server 2007 for inbound email to lists. To my knowledge, this is the only documentation out there on this topic. You can download the paper here: http://www.combined-knowledge.com/Downloads%202007.htm
Steve, Brett and Craig are pretty good with the SharePoint 2003 and 2007 technologies. I would encourage anyone in the UK or Europe to use their education and training services.
Bill English
Mindsharp