Hi,I've always found <package>@packages.debian.org as the easiest way to contact the maintainer and anyone involved, for example if I'm working on a particular package I'll contact the co-maintainers using that mailing list.
It is also good because you don't need to request for a mailing list where you don't really need one (in my case it's just 5-6 mails a month).
Cheers Antonio