AutoFlood now requires MessageQueue addon to work since WoW BfA patch 8.2.5 and WoW Classic 1.1.3.3 after Blizzard added some restrictions to the chat system.
See MessageQueue for more information about how to configure automatic messaging.
AutoFlood periodically sends a single-line message in a chat channel. It's designed for advertisement for guild recruitment, crafting, in-game events...
/flood [on|off]: Start / stops sending the message./floodmsg <message>: Sets the message. Supports hyperlinks to items, spells, crafts, achievements.../floodchan <channel>: Sets the channel. Accepted values : say, guild, raid, party, bg and channel number/floodrate <duration>: Sets the period (in seconds), minimum 10/floodinfo: Displays the message and the parameters./floodhelp: Displays this help message.
The settings are saved per character/realm.