Emails sent to comcast.net subscribers are bounced, delayed or NDR'ed
I work for a utility company that sends bills and payment notifications to people with comcast.net email addresses. I am seeing all of my emails queue up to comcast.net. I see the emails delay for several hours to several days and have received 2 NDR emails. This problem is recent as we have not made any changes and this email process worked fine in the past. I need my emails to get delilvered to comcast.net subscribers as these are billing and payment related messages where the comcast.net customers are also customers of my company. I see the emails bounce for hours or days before being delivered or getting returned.