I keep getting prompted to enter my "network password"

I just bought a new computer and I installed Office 2007. My ISP is Comcast
and I have been trying to get Outlook to remember my "network password" so
that Outlook will query the Comcast e-mail server w/o me having to enter a
password every time I want to send or receive an e-mail. I have also clicked
on "Save network password" every where I can and I still am asked each time I
click on "Send and Receive" to enter my network password. How do I tell
Outlook to remember my network password?