All Rafts have a Chat tab by default. This is where everyone in the Raft can send messages back and forth to each other to get valuable two-way information. Channels also have a Chat section (messages are the primary content type for Channels). Each Chat page on a Raft or Channel has a message composer bar into which you can directly type your message, which can include images, files, GIFs, and videos.
If you ever want to mute Chat on a specific Raft or Channel directly, select the "Info" ( i ) icon at the top of the Raft or Channels page, or go to the Messages or Rafts section of the notifications settings. Select Chat under Notification Preferences, and select Mute chat notification.
To notify everyone in a messaging group, include @everyone in your message.
To learn more about other types of messaging on Raftr, check out the following articles: