Salespanel’s browser extension helps track emails that are sent using Gmail and also get notified about lead activities.
Clicking on the plugin icon on your browser will give you an option to disable Gmail tracking and will also show you recent activities of your leads. You can also disable/enable tracking a particular email by clicking on the Salespanel icon at the bottom of the message composer and toggling the setting. Email tracking is otherwise enabled by default.
You can control notifications sent through the browser extension from notification preferences. Only account owners can change all notification settings.
Further Reading:
Functions of Chrome Extension and Gmail Tracking