First off,how long have you had this problem? Does it happen on other pop3 accounts or just the one? Try re-entering your account details.Open outlook,go to tools > e-mail accounts.Select [b:a5418fa460]View or change existing e-mail accounts[/b:a5418fa460] and click next.On the next screen highlight your account and select change.Re-enter all your details.Make sure you put a tick in [b:a5418fa460]remember password[/b:a5418fa460]. Click next,then finish. If the problem still persists,it is more than likely a logon encryption fault with your isp's mail server.Go to your isp's website and see if they have posted any news acknowledging that they have got a server fault. Good luck.