How to activate tracking for all emails by default
You can set Open & Link Tracking to activate automatically for all emails by executing the following steps:
1. Click the Right Inbox icon at the top right corner of your Gmail page, Then click 'Configure Right Inbox'.
2. In the configuration menu, click the first box next to 'Enable Email Open & Link Tracking on all emails'. Then click the 'Save' button at the bottom of the window to save your settings.