I’m late to the party here, but did you consider just paying for Mattermost? If it meets your needs, and your organization has 250 people, the cost for licensing is going to be relatively small compared to your IT budget (right?). They have “contact us” pricing, which means you can negotiate it.
I’m late to the party here, but did you consider just paying for Mattermost? If it meets your needs, and your organization has 250 people, the cost for licensing is going to be relatively small compared to your IT budget (right?). They have “contact us” pricing, which means you can negotiate it.