Organization Cannot Send me E-mails

Sooo.... I'm on the Board of a non-profit organization whose members can directly send me e-mails but when the batch e-mails are sent to the entire Board, they bounce back with the error code AUP#CXSNDR. We are talking about a non-profit. Tech support is non-existent. But this means I'm missing e-mails which are supposed to be sent to the Board, and it's become a huge issue at this point.

I've seen elsewhere that this is somehow supposed to resolve by me changing my password... forgive me for doubting that's the case, but also I really don't want to start messing with any of my settings if, in fact, this is something that Cox can fix better than I can. It does seem that Cox's system is simply rejecting this particular method of sending e-mail and that Cox needs to clear out that blockage.

Help?