The E*tractor Pro web-site is almost anal with repeatedly using the word
OPT-IN in their wording, as well as having a pseudo-disclaimer
'discouraging' people from using their software to SPAM.
Of course, this is bogus - after all, why would you need to harvest
addresses in bulk for an opt-in system - I think a good legal case can be
made by everyone involved (including ISPs involved) against the producers of
Extractor Pro for misleading advertising (possibly), but definitely for
fraudulent advertising.
In the meantime, our list is slowly starting to be overrun by these moron
spammers.
I do agree that it sounds like a good idea to use a filter and to remove
anything that has E*tractor Pro in the body text - add filterable words as
needed.