[exim] Integrating URI Blacklists into Exim

One of the best ways to detect spam is to look up the links within the
spam against URI blacklists like Spam Assassin does. But SA is slow and
bulky and I'd like to just reject at connect time just like I do with
other host based blacklists.

So - I'd like to suggest a feature. It would be an extension of content
scanning but something that would find the links in a message, look them
up against various URI blocklists, and cache the lookups just like other
lookup results are cached. I think this would be a very strong feature
to put into Exim for spam control.