There is a mailing list on gmane (gmane.comp.xfce.user) and this board.
I don't find it good, that two forums (mailing list and this board) are splitted. I tried also to post to the mailing list, but something is wrong with gmane. But nevertheless, one central point for xfce users would be better. Just my 2 cents.
if you want to post to the mailinglist register here:http://foo-projects.org/mailman/listinfo/xfce
gmane is only mirroring from that location afaik
And there are 2 ways of communication because not all ppl like fora and not all ppl like mailinglists... simple as that
and there are actually more ways... there is the wiki, the irc channel... etc etc..