email delays

On Tues at 3:38 p.m. I sent an email to 150 members of a club I run.  My own name is a recipient which helps me be sure the email was sent as intended.  I received my copy about 28 hours later.  My club's many members are at many different ISPs, most of whom get the emails immediately.  But people on my list with comcast addresses get significant delays too, though our copies don't arrive at the same time.       

This is unacceptable.  I need all my members to receive instant notifications of changes to upcoming events and even cancellations.   A day or two later isn't good enough.  

I see that Comcast is aware of this problem--many have complained about it here.   Realizing that, what I want to know is not why is this happening, but why is it STILL happening and what is Xfinity going to do about it?