In mailman2 there is a feature called ‘topics’. What this allowed you to do was create some filters on the list and when those filters matched mailman would add a header telling the user that this post was part of a ‘topic’ or not. You can then use the mailman interface to tell it you only wanted posts on a specific list of topics and no others. As far as I know there aren’t too many lists that used them, but there are a few we run in the Fedora Project that do: The prime example being the ‘package-announce’ list.

The package-announce list gets emails from bodhi (the Fedora updates system) about each update when it’s pushed into the stable updates repo. As you can imagine with a fast moving distro like Fedora, this list gets a LOT of posts. This list has topics for each Fedora release (22, 23, 24, etc) and also “Security” and “New package” updates. Using topics users could get a subset of these emails that they wanted.

Sadly, topic support isn’t yet available in mailman3, and it’s unclear right now when it might be implemented. Not wanting to hold up our migration to mailman3 forever, we want to go ahead and move lists like package-announce over as soon as we can. Of course this means those folks using topics are going to be in a bind. However, there are some alternatives:

  • You can switch to using a RSS feed directly from bodhi itself. For example: will give you all stable Fedora 23 updates. will give you all newpackage type updates, etc. Pretty much any search or page with a rss symbol on it on bodhi is an RSS feed.
  • You can set up notifications in the Fedora notifications service: to either email or IRC. For packages you are interested in, all updates, security or newpackage updates or any combo.
  • You can of course just stay on the package-announce list and filter things locally. You will be getting emails about some things you don’t care about, but emails are pretty small in this day of streaming video. 🙂

Hopefully those interested can switch over to one of the alternative methods above until topic support once again lands in mailman.