Off-premise chat for your business. Wonderful idea.
IRC, XMPP, any number of Discord/Slack clones that can run on-site, even Mastodon will use LDAP/PAM auth.
Stop using Slack for your business.
@r000t The problem here is that a purely internal communications platform is of limited use - you want to have third party project contacts in there, and they in turn don't want to run a client for each customer.
There's also the dependency on your own infrastructue - how do you communicate when your own systems are in trouble, and you can't authenticate to the chat service?
@r000t nah, just manage it and its risks appropriately and you're fine. The cost to operate a feature-similar onprem is high enough to justify offprem; I've never seen any of those clones that allow for proper retention protocol, legal discovery, remote mobility (no phone client that works without VPN? Sales won't use it), etc.
Besides, anything too onerous to use creates incentives to use unmanaged side channels. Gotta consider the whole risk picture
A Mastodon instance for info/cyber security-minded people.