Greet new and returning chatters

Welcome someone the first time they ever talk, and welcome regulars back.

Two separate greetings live here: one for somebody who has never talked in your channel before, and one for a regular coming back after a while away.

Open Welcomes & Shoutouts in the sidebar.
Turn on the master switch at the top.
Turn on Welcome brand-new chatters and edit the wording. {user} becomes their name.
Turn on the welcome-back greeting and set how long somebody must be away before it counts as a return.
Save.

Both are OFF by default, so nothing greets anyone until you turn them on. If greetings are not happening, this is almost always why.

It skips other bots and it skips you, and it is rate limited - a fifty-person raid cannot turn into fifty lines of chat.