Start Calypso. Click on the File menu, then Accounts, then
Properties, then the item for your mail account.
In the properties screen, select the Mail Server tab then click on
the Edit... button next to the Server Name drop down.
Click the Edit button on this screen.
Click the Check Box that says: This server requires authentication
Set the Authentication method to: Use POP account. Then click
on Ok till all of the dialogs are closed.