I use Z Creator to keep a large database of addresses for a free snail-mail newsletter I use in my marketing.  

I am always trying to add names of new prospects, delete defunct prospects, and, in general, keep the list clean.

I currently de-dup by dumping the list into a spreadsheet, sorting the various columns and using a simple formula to check for possible duplicates (If A2=A1 Print "Duplicate").  I then scan each possible Duplicate and decide to drop or keep the record.

Quite laborious, tedious, etc.

The process also misses duplicates as in "XYZ Corporation" is different from "XYZ Corp." is different from "X Y Z Corp."

Interested in suggestions or possible resources to help with this process.

Ideas and comments welcome.

Thanks.