We use a self-hosted Rocket.Chat instance with a maximum retention period of a couple of weeks, to encourage people against using it to store anything long-term. Almost all our internal emails are automatically wiped after a few months, for similar reasons.
The only organizational memory that's written down permanently is a wiki that we're all expected to keep updated with anything that needs to be known by others, and our source code repositories.
The only organizational memory that's written down permanently is a wiki that we're all expected to keep updated with anything that needs to be known by others, and our source code repositories.