There are a lot of List- headers here:
List-ID: felixge/node-sandboxed-module
<node-sandboxed-module.felixge.github.com>
List-Archive: https://github.com/felixge/node-sandboxed-module
List-Post: <mailto:reply+i-21866655-GUID-617481@reply.github.com>
List-Unsubscribe: <mailto:unsub+i-21866655-GUID-617481@reply.github.com>,
<https://github.com/notifications/unsubscribe/617481__GUID>
The only one we have is
List-Unsubscribe: <http://discourse.specifiction.org/my/preferences>
We can certainly add these headers:
List-ID, List-Archive, List-Post
It looks like:
List-ID = topic title, e.g. URL fragment? /t/topic-title/1234
List-Archive = topic URL
List-Post = duplicate the email reply address
The difference in Reply-To could also help?
Reply-To: felixge/node-sandboxed-module
<reply+i-21866655-GUID-617481@reply.github.com>
versus
Reply-To: domenic <discourse+GUID@specifiction.org>