No, it was inspired by another project called Ifile, that predates Graham's now famous paper "A Plan For Spam". It should be said however, that since the statistical approach to spam filtering became popular in the summer of 2002, a lot of ideas have been shared across projects. This even led to the creation of a Spam Conference that held its first meeting in Boston at MIT on January 17th, 2003 where many of the leaders of various filtering projects got together to discuss how to tackle this problem and where both Paul Graham and John Graham-Cumming presented their work.