Make sure you are still connected to the internet by accessing a different web page with your web browser. If you cannot then your connection has timed out from altohiway's end. Try redialling and downloading your mail again.
Maybe your mailbox is extremely large, if so you can use the altomail service to access your mail via a webbrowser and remove any unwanted emails before downloading.
Please see the article accessing my mail via altomail for more information.
