I have set under pop account/advanced/delete from server set to when removed from inbox so when i recieved mails on the iphone and then delete them. problem is when i start my macbook pro up the messages still appear there when i thought once i read them and deleted them off the iphone that should delete them from the main pop server, and it's the same the other way round to. Any ideas as i'm fed up with recieving them twice!
No. it is not the same thing the other way round. If you delete something from the client, they won't be deleted from the server. This is how POP works unfortunately. What you want is IMAP.