Cannot send email from program, only via website, getting blocked error

I have a Charter email account, and up until the start of this month, I could send and receive emails without an issue.  However, I now cannot send.  I get an error message:  The mail server sent an incorrect greeting:  impout006.msg.chrl.nc.charter.net cmsmtp 68.45.76.14 blocked.  I am then directed to the Charter website.  After speaking with people there, it appears this might be a block from Comcast that needs to be removed or resolved.  But I cannot get a way to contact someone directly, I get directed to the chatbot which only gives me limited options, and no way to type in a question.  Has anyone else had this issue and found an answer?