I am using this plugin to send chat messages from my Minecraft server to Slack: https://www.spigotmc.org/threads/slack.37113
I created a new instance of Mattermost, setup a new Integration for it, gave that URL in my Minecraft Slack config, restarted the server, and messages will not show up in Mattermost. Should this "just work" or does the developer of the Minecraft Slack plugin need to do something special to support Mattermost? My understanding was that it should just work.