We've had The Leanpub Authors Forum (https://community.leanpub.com/c/authors
) live for quite a while, and are still happy with it. (It runs on Discourse, which is open source, and it's very configurable. You can configure your email settings to make it how you want, etc.)
My number one issue with it is that not everything is there: we're also running this Google Group, and as such the discussion is split between the Google Group and the author forum.
It makes a lot more sense for there to be one community forum instead of two, so we're archiving this group. It will be in read-only mode with new posts disabled, so that the archive is still searchable, etc. Going forward, everything that would have been discussed here should now be discussed on The Leanpub Authors Forum instead.
Thanks very much to everyone who is part of this group for all their amazing feedback over the years. See you on The Leanpub Authors Forum!
P.S. If you have any issues joining The Leanpub Authors Forum, please email he...@leanpub.com