unable to send email over a dialup using smtp - error check port &

I am using outlook at email - while using a dialup, my toshiba has a firewall
and even when I disable it I cannot send mail. I am able to recieve mail from
both my local ISP ( Cable and wireless) and laso hotmail, but I am unable to
send email. The error message states that the server has been contacted but
there was not response and I should check the port or ssl. SMTP is on port
25. I do not know how to check which port is to be used for sending ad
retrieving mail ? . Could it be the firewall ? I have check my email address
and itis correct - I have recreated it to be sure

Thanks in advance
Gabby
email -
email -