email forwarding rejected: 550 message rejected ... AUP#CXSNDR

550 <xxxxxxr@cox.net> message rejected. Refer to Error Codes section at https://www.cox.com/residential/support/email-error-codes.html for more information. AUP#CXSNDR

On several emails I have tried to forward I have gotten the above reject message (Outlook 365, Windows 95).  Similar reject from iPad.

On one of the emails I found a link in the body of the email referring to http://click1.info2.xxxx ... for more information.  I am guessing that Cox thinks that "click1" link is spam because when I manually removed it, the email forwarded without any errors.

Did something change with Cox spam filtering?  Is there a solution to this?