Basically, I would want the code to try and determine which pieces of email were spam and which were not. Ideally, I could pass a string containing the text of the email to a function or method and the function or method would return some kind of rating or likelihood of this piece of email being a spam.
If it could also do mx record lookups or dns resolution or if it could use one of the popular spam blacklists or something such as that it would be great.
Like I mentioned before, the biggest requirements would be
1 - Easy to customize
and
2 - Non-cryptic open source code
