This article contains the necessary steps to install ContactMonkey for Gmail.
1. Sign up for a here. 
2. Install ContactMonkey for Gmail here.
3. Click "Add to Chrome" in the chrome web store.
4. Click "Add extension" in the pop up.
5. Close Gmail and then relaunch Gmail.
6. You should see the ContactMonkey sidebar on the right hand side of your screen and you can now log in.
If you do not see the sidebar please refer to this troubleshooting article.
We recommend signing in using SSO, i.e. clicking “Sign in with Google”.
7. Check your inbox for an email titled “Let’s Test ContactMonkey!” and follow the instructions to help you test your email tracking.
Watch a video on getting started with Gmail here.