Yes, the Guest Account feature allows organizations to collaborate with external users within a controlled environment. See the Guest Accounts documentation for more information.
You are welcome to use the open source Mattermost Team Edition and its extensive API library to build your own solution.
Mattermost Enterprise Edition is designed for self-hosted, enterprise-grade communication. It’s not recommended for primarily providing customer service or customer support, and does not currently offer a licensing model nor technical advice for this use case.
If you’d like to create an open source derivative version of Mattermost using the
/mattermost-server source code to support your use case, please see below.
Not yet. You can upvote the feature proposal online to add your support. If you create such a plugin, we would love to see it open sourced and made available to the community.