On occasion, your computer fails to update DNS records correctly, resulting in internet pages not loading or email not downloading.  To correct this, the computer's DNS cache needs to be cleared.

In Windows XP, left click on the start icon, and click on "Run". 
In the window type "ipconfig /flushdns".  (copy and paste the text between the quotation marks)

In Windows 7, click on the start menu, click on the start icon, and type "ipconfig /flushdns" into the "Search programs and files" box.

In Windows 10, click on the start menu, and simply type "ipconfig /flushdns", and press the Enter key.

You might have to restart your computer.