You can "mute" tracking notifications for messages through your Gmail account. Tracking can be disabled through the Events Dashboard by using the "Stop Tracking" option.
Within a thread, tracking can be disabled by clicking on the Tracking icon at the top right of the thread, and then toggling OFF Tracking.
It can also be disabled by un-checking the "Track" checkbox that's to the right of the small Yesware icon in the lower left of a new e-mail before you send an e-mail.
You can also turn off global message tracking by going to the Yesware drop down within gmail, then choosing "Preferences", then "Compose Options", and set "Track Opens" to OFF.