Replacing Mailing lists: Email-In

I’m unclear on something:

Will there be an option to allow topics created by non-existing users (aka strangers)? I would very much like that.

Our basic way to prevent spam would be:

  • Maintain a whitelist of allowed e-mails (based on our e-mail subscribers)
  • Make all first-time posts hidden by default. If that email has had 2 posts made visible, future posts will be automatically accepted.

@erlend_sh, there currently is, but only on a category-bases (so users could mute the category if it comes to worst). You can activate it by giving a category an incoming email-address and check the checkbox under it. Emails from strangers will then be posted by the system user referencing the original email-address.

Thanks, that’s good news. Is this live on as we speak? I’d love a basic manual on how to use it so I can make a few tests on Try.Discourse.

This part I don’t like, though I realize it’s tricky. So if I start out interacting with a forum by e-mail only, then decide to register later, my initial posts will belong to the system user?

Couldn’t we just create a new user based on the e-mail? I realise this would not be desirable for many, but if you have a whitelist the chance of spammer accounts would be minimal.

Actually, thinking of the Support-Forum and CRM-System approach (which is a little how we are using it), I was thinking of building a “ghost”-accounts system: accounts handled by third-parties like apps (a twitter account for e.g.) but also the mailing system, so when the same users emails twice, they are understood as one user. Like in this case, I’d love for a user, who joins later to get their emails attached to them, but as a support person I might also simply be able to look up our conversations with them and refer to one profile account (with potential meta-data). And if I answer the post, I’d also want the system to send that person behind the ghost account this answer as an email-reply.

But all of that is way out of scope for a discussion here, needs way more discussion and is by far not needed to fix the use case at hand (described above), so I went for the simpler system first. I’m open to discussing this kind of system though, too.


Hi all. I’m the creator of a different group discussion platform called Lumen. It was designed with email-in from the beginning. You can check it out at if you’re looking for ideas of how to go about things.


Is the current feature set documented anywhere? I found the “email_in” option in settings, but how do I target a specific category for instance? And if I’m set up for replies by e-mail am I good and ready for new posts too?

Also, is it safe to rename a category after you’ve set up a mail for it?

What about moving the category? E.g. from child-category to parent category.

The ‘custom incoming email address’ is the only thing that really matters there.

@lightyear, I am quite interested in what your actual experience is with replacing Google Groups with Discourse?

I am consulting with a large, multi-billion dollar Silicon Valley chip company that is using Lithium for forums and Google Groups for mailing lists.

They are creating a Linux User Group for hardware hacking. Part of this may deal with kernel patches. They want to have a forum for discussion on “cool hardware hacks” (like 3d vision processing for autonomous planes) and a separate mailing list for driver patches to the Linux kernel or embedded Linux distribution updates. I would like to recommend that they just use Discourse. However, I have not been able to compare the feature set of Discourse as a mailing list replacement for GoogleGroups. I would be interested in your experience.

There is some connection to their GitHub repository and I imagine that the mailing list will have code snippets. If I look at the Linux Kernel Mailing List, they appear to actually use the mailing list to exchange some patches. Is that correct?

The Linux kernel mailing list is primarily used for sending around patches to the kernel, and discussion of said patches.

I also noticed that the incoming emails from unregistered users (the ones that get posted by @system) show the e-mail address of the poster. I find this very worrisome. I could be sending a ticket to support, completely oblivious to the fact that my e-mail address is being made available on a public forum.

Then the support of your company sucks, obviously. After the first post they’d be very aware that these email addresses are included (how else should you know how to contact them otherwise) and I hope they either disable the feature or move it into a private category (which is what we are doing).

We have only little emails on the mailing lists and they are primary for discussions, support and other non-code-related stuff. The kernel ML is indeed mostly about sending around patches and if you want to have something like this I’d not recommend discourse ATM. The support for real-email-patches in GIT and other tools is high, while discourse poorly manages patches-like files, merge-requests and alike at the moment. That said, I’d personally recommend Github and Pull-Requests (or your custom hosted Gitlab) alongside a discourse instance – like done here on meta. With this combination (and an IRC-Channel for direct communication and support), I don’t see the need for any noisy Mailing list (or crappy google groups).

They should absolutely be in a private category. I went at it from the wrong angle. All I really meant to say was that there ought to be a prominent warning in the Discourse settings panel (been wanting tooltips for a while) for things like these, because there is a big difference between e-mails sent from knowns and unknowns.

So, this is also kind of a hack to allow people to post to a private category that they do not have access to…

The only thing that makes it less ‘email like’ is that you can’t reply directly to them, and you can’t add new people to the thread.

When you get a message in this private category, what do you do? Open your email and reply to the person? Or create a new private message to them?

It’d be interesting to eventually have a separate permissions for “Topic Creator” and “Mentioned Users” so that a conversation can be ‘opened up’ to certain users within a private category.

Wow, great recommendation. This is what I’ll recommend. I know they already have a GitHub system open to the public to manage stuff like driver patches. I actually think that most of the patches are coming from in-house staff at the moment. However, they hope to change that mix with training, developer events, a new forum, and project highlights. They are also coming out with new dev tools. Great point about IRC. I already suggested that they set something up on after we clear the first hurdle of the forum.

I think I can just show the guy that hired us the interaction between GitHub and the dev community here on this forum. With the blowout number of stars that Discourse gets on GitHub, there’s clear proof that this method works. Follow the leaders. Much thanks for the info.

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Just a quick bug report.

If you email a new thread to discourse but you do it via cc or bcc, discourse does not consume the email. We are in a transition period between google groups and discourse, and I noticed this when trying to post to both mediums.


@jhogendorn , thanks for sharing this bit of usage insight. I hear questions about mailing lists come up all the time. I personally would value updates on how people are moving from Discourse to mailing lists. I think that I’ll need to experience the transition first-hand to really understand how it works.

I’m rather fascinated why both IRC and mailing lists seem to be the preferred method of education for many highly technical groups. I did an analysis of 10 communiities and many of them were based primarily on mailing lists.

  • Android (Google tie-in makes easy to understand by GoogleGroups)
  • Yocto Linux (This one has approx 15 mailing lists for an obscure project)
  • Fedora

The Fedora example is interesting because they have granular discussion lists, including a list specific to women that use Fedora.

I’m still trying to understand the flow to see how the topic taxonomy translates into a specific mailing list. I’m also a bit new to the terminology:

  • Groups of mailing lists = one Discourse community

  • Specific mailing list (such as women using Fedora) = On Discourse, what is the proper term?

  • subject in mailing list = topic on Discourse (is this correct?)

  • digest of mailing list = digest on Discourse (is this correct?)


I would get out of the hard core tech ghetto there, though. What surprises me is how often non technical groups have mailing lists. And they even like them.


For a lot of people, email is a very acceptable or even prefered ui/ux. ie, having the content delivered to you in real time and being able to respond easily, in whatever your favourite software is, is surprisingly useful.

I’m not sure how other groups utilise mailing lists, but we ran just the one and we’ve moved to a discourse instance with 4 or so categories. Since I’m running it and I’m of the opinion that less is more, it will probably stay that way. You can see our instance at


Hi @lightyear I am glad through this latest discussion about yahoo to come across this post and to learn about the background to the mail in functionality. I’d be interested in helping with use cases and testing, and have thought alot about this on other platforms over the years. PM me if you want help with testing, or let me know how I can help.