Can receive emails but not send emails

I can receive emails with my comcast.net email but cannot send emails. All info is correct, I have compared to my family to ensure everything is accurate. My password is certainly correct as I have reset it just for this issue. The error message is “Cannot send mail” “The connection to the outgoing server smtp.concast.net failed. Additional…”

Please help me to solve this issue as I am very sure all my information is accurate and after deleting from my iPhone, restarting my router, changing my password, searching through forums, and logging into the Xfinity site to ensure my info is correct, I am still unable to get everything to work.