I have an external email client which I've pointed my outlook to pick up emails from. I initially set it up so that all the emails that are being sent to that email, be sent straight to a new folder which I've created specifically for it. However due to errors, I had to re set it up and, again set it so that the email was being sent to that new folder. But now, because of that, every time I get an email to that folder, it comes in twice.

I've checked the "make rules" option and currently it says there are no rules. How can I make the double emails stop. Is there a specific folder option that I can look at?