I've worked only in a couple of non-profits and every couple of months I get this question:
Can we opt {certain group} back into email?

I always reply NO!

Because it's a non-profit organization, people tend to think that CAN-SPAM does not apply (if they know about it). But the real worry for me is deliverability.

I have to write up the reasons every now and again. Does this ever come up with anyone else and do you have a go-to response?