When sending out a broadcast, such as a newsletter, I think it would be useful to have a feature such as "smart sending".

Ideally that would be a check in the "send or schedule" view, that when selected avoids to send the broadcast to all the contacts who have already received another communication in the last 24 hours (or similar/choosable time period). Eventually, it could also schedule the message 24 hours after the previous one.

I think that would be useful to avoid "broadcast overload" on clients.