If you're using the Mac or PC Google Drive app, you can only use one account at a time, no matter what. If you use the Android app, you can switch between any Gmail accounts on your device from within the Drive app, but it won't sync them. There are many free mail services in the market among them two biggest competitors are Outlook and Gmail. Outlook is an email service prov@ided by Microsoft and Gmail is also an email service prov@ided by Google. If you feel technologically confident enough to sync contacts between Gmail accounts just by using Gmail itself, then go for it. But if you find it too confusing or not worth your time, then you can use software like PieSync instead. If you've enabled syncing all your emails from Gmail to Nutshell, A "Nutshell" label is automatically created in Gmail and applied to those email. Nutshell does this so you can quickly identify which emails have synced to Nutshell from Gmail. You can hide this label by following the steps below.