Outlook 2007

I set up 2 POP accounts on Outlook. I use one or the other POP addresses when i send emails depending on who they are. For some reason emails I receive either from my contacts or unsolicited go in to BOTH accounts as duplicates. I am thinking there must be a way to change my account settings to prevent this from happening. But so far have not been able to find a solution, please advise

Well, he only uses outlook because it was set up for him. although i do like thunderbird