Sorry for the delay guys - been busy

I did contact my ISP and he made a few settings changes but to no avail. I have a POP3 account with settings:
Incoming mail server: pop-server.roadrunner.com
Outgoing mail server (SMPT): smtp-server.roadrunner.com
I am taking online courses from a University with a perk of being able to download online Microsoft Office Professional Plus 2010, which includes Microsoft Outlook, of course. (This is FREE, but maybe the problem is with the Outlook software as suggested by the ISP guy, so it might not be really free). Another observation - when sending an email to me, I can see it come into the Roadrunner online Inbox. Then if I receive the message on old computer first, it doesn't come into my new computer. If I receive it on my new computer first, I do receive it on the old computer as well!! Weird