Password reset e-mails sent to comcast subscribers from Okta returned as dropped "Spam Reporting Address

We use Okta as an Identity Access Manager to allow our customers to access a hosted application.  If users forget their password, they can click a link to send a password reset e-mail.  Customers are reporting that they never receive the message and upon further review, Okta is reporting the e-mail delivery as dropped due to comcast reporting that sender is a "Spam Reporting Address".  I have tried submitting the form on Comcast's Postmaster / SPA website using the sending IP address and domain; however within seconds I get a message back saying that the IP address is not on your blocklist.  What is the best way to find resolution to this issue?  I'm assuming the problem is on Comcast's side and not Okta.