For some unknown reason (even support had no answer to why), they decided to change how preview emails were sent out.
It used to be when you sent a preview email out to multiple addresses, those addresses would be included in the To or Cc. So if one of those people had a comment they could reply all and allow everyone to see it.
Now when you send out preview emails to multiple addresses, each address just gets the email but doesn't see the other addresses. So now the person that sends it has to send a preview themselves then forward preview email themselves to other addresses.
This is extra work and we do not understand the reason for the change.
At least give us an option to check or something.