... does not having a mailing list really encourage people to "collaborate through ikiwiki itself"? Personally, I strongly prefer to participate in mailing lists via my mail/nntp client. I follow over 50 mailing lists, so if I can't participate in a mailing list mail or nntp, I'll probably just not participate at all. I suspect there are others in my situation. I think that by not having an SMTP-driven mailing list, ikiwiki is passing up a big opportunity to build community. -- AdamMegacz

If you want to gate ikiwiki's various rss feeds to email, that's trivial --Joey

Also see this wishlist request. Sure, you can collaborate with RSS and a wiki, but the ikiwiki community is not only made up of developers.