Read tracking lets you know if the email you’ve sent has been read or not and Canary lets you do just that.
Read Tracking on your iOS device
On your iOS app, Read Receipts can be enabled from the App Settings. Open Canary > Settings > Toggle On Read Receipts under Composing.
Check which of your emails have been read by clicking on your Read Activity via Dashboard.
All read emails will be displayed on your Read Activity.