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TODO: Shall we limit Team messaging in any way? E.g. can only Team admin's send messages to Teams? Shall we only allow messaging to small Teams? (We could even combine the two and allow all small Team members to email each other, but for large Teams only allow admin's to do so.)
MIKE: A suggestion - changing behavior based on Team size seems arbitrary, and likely to cause confusion in the use base. My proposal is that Team Managers can always send a message to all Team Members. Team Managers can change a Team configuration option "allow Team members to send messages to the team". Now, we've converted out debate into what the default should be. I feel less strongly about this, but would lean towards allowing the messaging, as I think it will be useful and not abused in the majority of the cases. But for cases such as the Challenge "All Users" teams, we could flip the switch the other way.
Each message will have a "one-click unsubscribe" footer, facilitating update of the recipient's notification settings to suppress email delivery.
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