I apologize you're contacts are not receiving this email as it should! However when taking a look at your account I can see you were able to speak to our Phone Support about this experience as well. They were able to determine this experience is a defect we are in the process of troubleshooting. In fact there are a few more details we would like to collect from you:
We will submit a ticket for this experience in your account and add you to our queue to be notified when this is resolved once we receive these details. In the meantime we suggest, removing your address from the list and then re-add the contact back to the list.