URxvt.perl-ext-common:
URxvt.perl-ext: default,mymatcher
URxvt.url-launcher: firefox
URxvt.mymatcher.scheme.1: mailto
URxvt.mymatcher.launcher.1: claws-mail
URxvt.mymatcher.button: M-C-1
URxvt.keysym.M-C-Return: perl:mymatcher:last
URxvt.keysym.M-C-Tab: perl:mymatcher:list