If you haven't seen the official notice, the CPAN Testers project is migrating from using email to send reports (CPAN Testers 1.0) to using web-based submission (CPAN Testers 2.0). As of September 1, 2010, the old email list will be shut down and only web submissions will be accepted.
I've just updated the "quick-start" documentation on the CPAN Testers wiki: Quick HowTo for CPAN Testers 2.0
It's not perfect, but it's a lot better than it used to be. If you are still submitting reports by email, please read and follow the instructions before the end of August. If you have trouble, please ask for help on the cpan-testers-discuss mailing list or on #cpantesters-discuss on irc.perl.org.