Question : telneting into smtp server, what reply to 'authenication required'?

I'm having trouble sending email through a comcast smtp server.  Customer service has no idea where the problem lies.

So I did some reading and found that I could do some testing by connecting and sending an email through telnet.

So I connect ok, do the 'helo', the 'mail from;'  and then the server says 'authentication required'.  I don't know how to respond to that.  I tried typing in my username, expecting it would then ask for my password, but it didn't.  What does it expect from me?  How should I respond?  

Thank you,   Chris

Answer : telneting into smtp server, what reply to 'authenication required'?

Hi

Can u trying doing a telnet to the localhost as in Telnet localhost 25 instead of the targeted SMTP and then try sending an email to any of the internal users.

Temme wht u get .. am waiting ...