Hello, Eli –
Thanks for suggesting that workaround, I had thought about doing something like that myself. The issue for me, at least, is if people hit unsubscribe on that temporary mailing list, they’re still subscribed to the main list, so they might get irritated at receiving future mailings. I do hope that the developers come up with a solution. Since the plugin appears to log what subscribers have been sent a newsletter, it should be rather trivial to have some code that compares the table of current subscribers with the list of past recipients, and send an existing newsletter to those who were never previously sent it.