Unable to Send Emails (Comcast.net)

Hello

I have a comcast email account that I am unable to send emails through. I can receive and read all incoming emails, but when I type to send on the network, they will either fail to send, or be stuck in que in the Outbox.

I have found a remedy to this by switching networks to 4G to send, and they go along right thru.

I cannot see how I am able to fix this on my end, so am reaching out for ideas so I can use my home & work like I have been able to use in the past

*(Note) Previously was on a different network provider, and currently using Starlink.

Other email accounts w/ different providers have all been unaffected by the Network switch for context.