PLEASE RESPOND - EXTREMELY IMPORTANT - COMCAST BLOCKING ALL CLIENT COMMUNICATION

I work for a large investment firm called Baird. We have a fiduciary responsibility to our clients which includes being able to communicate at all times, especially during the coronavirus pandemic. We're having an issue that seems to be isolated to customers with comcast.net emails that I'm hoping I can get help with.

What we've seen is that even though our email tracking is saying that the emails were delivered, these customers don't report seeing the emails in their inbox or spam folders. This is a very trying time for our customers so any help here would be very much appreciated. We have millions of clients with comcast email addresses, so fixing this as a whole is our main focus.