Outlook not downloading emails

About 2 weeks ago, outlook stop downloading my emails. When I go to webmail, I am still receiving mails. I did not change any setting whatsoever on the outlook. And I am using Outlook connector for the setting up of the emails, and therefore i cannot check the accounts set-up.
I learned that I am able to send emails, sometimes.
I have cleared some of my mails in the webmail also.
Please help.