This may be an off-the-wall sort of question but I was wondering: Has anyone ever run across a situation where an in-house listserv has been implemented instead of paying for a company subscription to something like Slack, Hipchat, or similar?

I'm wondering why something like listserv shouldn't be considered. It seems it would to be more cost effective than using a 3rd-party application and it doesn't require anything special to access assuming everyone has access to email in the company (and who doesn't?). Host it in-house. Host it in "The Cloud(tm)". Who cares?

Do these commercial products just exist to cater to the buy-not-build crowd?

Not GUI and therefore dismissed out-of-hand? (I.e., not sexy enough?)

Too likely that the legal department would balk at having these emails around just waiting for a discovery request? (I'd counter that a HipSlack dialog could just as easily be requested but IANAL so don't know the way something like that would wind up working.)

Note: my reading pointed out that listserv was freely available up through the first third of the '90s before it went commercial. The freely-downloadable version is somewhat limited but would probably still work for a small company. Older sources could surely be obtained from the 'net and be compiled to be usable. It wouldn't surprise me to find an old SRPM on one of the ancient RedHat CDs I have in the basement.

Thoughts on this?

Most of my recent experience has been in shops using either Lotus Notes or Outlook mail servers. In both cases, they managed in-house lists by setting up special email address that delivered mail to all of the members using those systems.

That could be implemented in a Linux sendmail or postfix environment with an email alias to do the same thing. Something like:
No additional software required. Some challenges around maintaining the alias. Perhaps an internal web page could be built?

And, there's GNU Mailman, which is pretty full featured and still free.

Have you considered third choices, such as Jabber (OpenFire is really easy to set up) or a local IRC server?

While that does get the word out when someone sends mail to the alias, I'm wondering how much of a hassle it is maintaining the history of a discussion. It seems to me that someone--or everybody--would have to retain all the communications on a particular topic. I guess I was thinking about something like an internal newsgroup. Most Notes (if they're even still being used--the last company I worked for using Notes abandoned it about 10 years ago) and Outlook sites will almost certainly have rules set up to clobber emails older than some fairly short time frames--that legal requirement I alluded to in my initial post--so the origins of a discussion would disappear obliterating the whole intent of a discussion. (Unless everyone keeps the entire discussion in an ever-growing email that just keeps getting appended to. That'll get unwieldy before long.) Going back to a discussion would be sort of like coming into a theater during the last 30 minutes of a movie. Not terribly useful to point someone new to the team to the discussion if much of the early bits are now gone. Of course, I suppose that those time limits might be imposed on something like I've been wondering about so history could still be lost.

In-house web forum? I've not seen any that people wanted to use. Wiki? Ugh. Needs a professional curator to be useful. (Case in point: try looking up anything fairly technical on Atlassian's wiki. Multiple people chiming in on a subject and going in as many directions as there are contributors. You'll be tearing your hair out in no time.) Plus I don't know what it is about web-based discussion sites as implemented by companies for internal use but they always make it a major PITB to attach images/screenshots/documents to posts if not banning them outright. Probably why I haven't seen any popular within the companies where I've encountered them. Could be that the wrong people are running them. Who knows. (But I'm getting a little off-topic though maybe this illustrates my interest in exploring alternate means of doing internal communications.)

I do recall seeing that ages ago. I ought to give it a look. I was thinking that, with the commercialization of listserv, I might have to go back to some really early RedHat, Slackware, or other distribution's source files to find something.

The last place I worked that used Notes abandoned it only about a year ago.

You make some excellent points. I never much liked how those things worked in either environment.

Re: GNU Mailman. I recently upgraded my web server and decided to abandon majordomo as the list server...it is not maintained and just doesn't play well (that is, not at all) with the current SPF and DMARC configurations of the larger free email sites.
Mailman is currently supported. Has a newer version (Mailman3) I haven't tried yet (my python installation wasn't up to snuff, as I recall) So far (about 4 months) it has worked very well for me and my customers.

Good to hear. I started looking at the documentation for mailman.

At the end of the day, it's all just IRC. Everyone's phones these days can run some kind of VPN natively (and OpenVPN can be installed on any of them). (Or maybe you can just use SSL in this case, if the server is set up to check the certificates that are presented by each client.) So you set up a secure connection from each phone. IRC clients are easy to come by. I have never found any compelling advantages to services like Slack.

Oh. I did not know that Slack was a messaging tool (IRC, yes)...I was responding to the "listserv" in the OP.
I can't even recall the name of the Notes built-in "Instant Messenger" <getting old...> and I'm not sure what they switched to when they dropped Notes and went with Outlook for mail...maybe Skype??

I've never been a big fan of housing internal company business on someone else's computers though I know of plenty that do--we all do. I've used Slack and Hipchat at work as well as Microsoft's tool--whose name escapes me at the moment--and all had pluses and minuses. In some cases, though, people had to jump through all sorts of authorization hoops to gain access to those tools; probably due to costs. I was looking/thinking more about a simple (mostly text-oriented but with the capability of including project-related graphics/attachments/etc.) in-house solution--not something that would be internet facing--to support project discussions. Opening that up to the world and having to lock it down would be daunting to say the least. And for me, I will not put work-related tools (other than phone numbers) on my personal phone. (If the company wants to supply a phone, they can put whatever they want on it.)

I can't recall what the MS tool was. Communicator, maybe? It was actually fairly decent but I've used it at two different sites and it was a wildly different experience in each case due to either the way it had been implemented or licensed--or there was a version change--and the "user experience" was good at the first site and pretty awful on the second. Both were after MS had bought Skype and it was being integrated into the MS product.

BTW, I'm not clairvoyent or anything like that but this announcement is apropos to this thread:

Slack Is Shutting Down Its IRC Gateway

Same thing for AOL. No more AIM.
The Facebook IM is all that's left, I think.
Probably an internal IRC server, as suggested, then?

For what it's worth, my LUG recently abandoned it's long-standing mailing list for a phpbb forum.

Have you considered talking to some of your more accomplished users for their input?