When I change group membership, an email goes out to everyone in the group alerting them to this. This might be fine for other DC users, as DC handles this email. But users of other MUA’s really don’t want to see it. It just looks weird. They respond – “what group? did you sign me up for some group? unsubscribe me!”
The “groups” is a concept that is internal to DC. No one else knows about it. We should not bother other people with this concept.
When I add or remove people from a group, no emails are generated.
When I add or remove people from a group, that generates a message to group members.