Google Contacts Not Integrating with Email

I use a POP3 email account and Google contacts. The contacts appear in the Contacts tab but not when I compose emails. When I click on the "To£ button in the compose window, the contacts do not appear.

Hello Laurie,
if you click the To button a Select contacts window whould appear and you should be able to choose which contact folders you’re searching through. Try changing it to All Folders to make sure you can access all available contacts.
If the option is not there, could you please screenshot the Select contact window for me?