On Sat, 8 Jun 2024 at 17:24, James Knott via talk <talk@gtalug.org> wrote:

I'm on Rogers and while the IPv4 address is DHCP, it changes so seldom,
it's virtually static.  They also provide a host name, based on modem
and router MAC addresses, that doesn't change unless you change the
hardware.

Try setting up your own mail server with an address from the DHCP pool. Most or all of mail sent from such IP address will go straight to the recipient's Spam folder.