You can configure Mailtrack so that it doesn't track by default every email you send.
To do so:
1) In your dashboard, click the gear icon at the top right to open Settings & account.
2) Click Tracking.
3) Turn off Track emails by default.
You can also turn off open tracking for a single email. The email is still sent through Mailsuite, and any tracked links or documents you've added to it are still tracked. To do so:
1) In the Gmail compose window, click the Mailsuite button next to Send.
2) Uncheck Track email opens.
3) Send the email.