My email isn't deleted off yahoo when I delete it from Outlook & .

I have Outlook 2003. Every time the I try to delete mail from Outlook (even
empty deleted items) the email comes back in the next send and recieve
session but instead of one email there is 2 then 3 then 4 etc. of the same
message. I have checked setup and I have tried to every different option
about deleting messages. What do I do??? please help email me at
epiekarc@yahoo.com