The way it usually works is that the web page is screened by the ship's servers (or any server that supplies net service for a public area) for offensive content. This might be based on location/site of pictures (for catching pornographic images) or based on text (black listed words). Computers are not smart enough yet to be able to consistently recognize banned images based on image recognition algorithms (though that is not far away from becoming commercially feasible).
So, the problem that Chip experienced might have been because one of those banned words was in the SUBJECT of the email sent to him. If it was, when you try to access your inbox and it lists your incoming emails and their subjects, it tries to display the page and the filter catches the banned word and prevents the inbox from displaying. This obviously is a problem since it prevents you from getting to the inbox at all to delete the message so you can go about reading your regular mail.
Unfortunately, no good solution to this except setting up a sterile email address (one that doesn't get used or handed out except for emergency purposes and has enough complexity to the address such that it can't be hit upon by spammers by brute attack random email generation) or to set your spam filters to be extremely sensitive so that they shunt all these emails (and possibly some of your desired emails) to a spam folder.
Arlene - the email account you talk about above gets hit with spam because you have a link to it from your website. It got harvested from there, most likely. Do you have your email address actually displayed or do you have a script that emails you when somebody presses a button?
Masaki