This problem has been solved elegantly by several companies who sell mailing list management software.

Check out
http://www.hallogram.com/mailers/



>>A coworker wants me to build a routine that will search a dbf for duplicate addresses. A simple task if we were looking for an exact match. However he wants me to use "fuzzy" logic so that the match doesn't have to be exact, just "pretty close". I haven't a clue how to go about this. Is there a routine around that I could use as a sample to get started?
Thanks