In group Settings, there are a handful of Member Notices that Moderators can create. There is a Welcome message that I think all groups get by default. Another one is "Rejected Message", which is said to be the "Message sent when a message is rejected".
What does that mean?
I thought it meant that it is sent whenever an incoming message was rejected. But not, apparently.
Most rejected messages are ones sent by unsubscribed addresses. When someone sends a message that is rejected for that reason, they do not receive one of those "Rejected Messages". Instead, they receive a cryptic reply (which for me implies that Groups.io is "misconfigured", until I read further down). Everything that I wrote in the "Rejected Message" message is apparently of no use because that message is not sent.
Is the problem that Groups.io fails to send that message when an incoming message was rejected?
Or is that message used only in a subset of cases -- and if so, should the name or its description be changed to reflect the more restricted usage?