So i search for poppler on google and find http://www.linuxfromscratch.org/blfs/view/svn/general/poppler.html a page from the Linux From Scratch project that mentions how to build poppler. I spot a couple of factual errors there and after some searching i see i have to mail firstname.lastname@example.org which i do.
After an hour or so i get a mail saying my mail has been rejected to enter the mailing list.
After querying the admin of the list i get "IIRC, you are not registered with the list." That's it, not a "please for bugs use thisOtherService this list is for core contributors", not even something like "Please register, we prefer people to do so it makes sure follow ups are not lost", nothing.
So good luck with the project, if you don't want to include fixes it's up to you, but you should make contributing easy otherwise you'll end up with no incoming people and you'll project will die sooner or later.
I'm glad KDE community is generally more welcoming than that.