Why I can't get or send email through Xfinity to my email server yet I can when I use a cell network

Since 5:01 August 6, 2026 I cannot send or receive emails to my email server using the xfinity network. I can however send and receive emails via my backup cell network to this email server. I have several email accounts and only 1 is affected, my personal email server living out on the internet. My email server is working fine as I can access it through xfinity and cell networks. Something is blocking the SMTP protocol to my server on the Xfinity network.

So obviously there is a problem on the xfinity network. Doesn't seem to be any published way to contact anyone at Xfinity and explain the problem.