spam detector false positive repeatedly

This is the third or fourth time Comcast has blocked my email "[Edited: "Personal Information"]".  I recently spent about an hour getting past AI and talking to a human.  He assured me that the problem was resolved and would not reoccur.  But a test email did bounce.

[Image removal: "Personal Information"]

I have an outlook vba program that sends out a "mail delivered" message to a list of email addresses.  It has worked for all addresses for over two years, except four or more times spontaneously comcast.net, and only comcast.net messages get bounced with the above message.

This is the list of addressees: 

[Edited: "Personal Information"]

Notice that three of them are comcast.net addresses.  If Comcast/Xfinity uses an AI bot to bounce suspected spammers, it would be intolerably foolish to not support a "whitelist" of previously mis-identified addresses.  I ask that [Edited: "Personal Information"] be added to that whtelist if it exists, and insist the it would be dangerous practice to not implement one.

It is frustrating that the support person I spent nearly an hour talking to promised that the issue was resolve and would not reoccur.  Yet I am still being blocked