I currently have comcast and a comcast.net email account. Recently emails I send to verizon.net accounts do not go through. I do not get an error message, they just fail to get to the intended receiver. Comcast tech support checked all my email settings on my computer and they are good. I can send emails to verizon.net accounts if I go to the Comcast.net web site and log into my email account there. But not from my windows mail on my computer. I have high speed internet service via comcast.
I have also sent my ip address to Verizon's whitelist and they say my IP is not being blocked.
Thanks