It's a mailinglist if you can actually send mail to it. As an author of CPAN modules, I'm not interested in mail I can't respond to. I have a name for such mail: it's called SPAM.

I publish an email address on all my modules where people can report bugs or problems. I have a CPAN id with corresponding email address people can send their mail to. People can report bugs via the RT system. That's enough I'd say. I really don't want to hunt perlmonks, comp.lang.perl.m{isc,modules,moderated} and god knows how many other fora people think is nice to have to discuss CPAN modules.