Trying to put this email burden into perspective, I've just done a bit of simple math on our main group.
In December we received 379 individual messages from our members. I base this on the message numbers in our archive.
Our December 31 membersip was 3892 but I figured to usinng 38i50 average members which is conservative for our 20 year old group
Doing the math based on premise that all members received individual messages, groups.io transmitted 1459150 total messages to our members.
Doing the math based on premise that all members received digest, each of 12 messages, groups.io would have transmitted 121595 total digests to our members.
This would have also reduced the compute burden just for message transmission to 1/12 of individual message transmission burden.
BTW it would have also reduced each member's supplier's burden by the same amount.
Of course if all members simply used the online messaging the burdens would be a great deal smaller.