Emails from one specific sender not being received.

I have stopped receiving emails from quickbooks@notification.intuit.com.  I have been receiving these monthly for several years without a problem, but around three months ago they stopped.  The sender confirmed they were still sending them. I use Outlook, but have been checking for them also on the xfinity website interface and they are missing there as well. They are not  in the spam folder. I had a similar problem a few years ago with emails from the postal service (Informed Delivery) and a representative on this forum fixed it for me. I can't find the thread, but he had noted it was a service that xfinity used to proactively filter out junk at that time that was blocking them.

Help would be appreciated.

Thanks