and no involvement with SORBS idiots is required.
If you don't like SORBS, don't use them.TOR doesn't try to be invisible .. if a site admin wants to block anonymous ($whatever) .. they're free to do so, and SORBS just makes it easier (the TOR dnsbl).
Statistically speaking, the volume of non-legitimate email coming from anonymous routers makes TOR a pretty easy target.
Cheers, Michael Holstein CISSP GCIA Cleveland State University