In my experience the optimal way to manage a Gmail account, is either using an Android device and setting the Gmail app appropriately, or through a browser getting to the Gmail site page.
Trying to get to work Gmail with a different email client is leading to mixed result. In this case if you are still relying on the old POP3 protocol and using different devices to manage your electronic messages, I recommend reading the following Gmail help page
Using POP on multiple clients or mobile devices
