To set Canary as your default email client, follow the below mentioned steps-
macOS
You can set Canary as the default email client on your macOS via Apple Mail’s preferences. Mail > Preferences > Default Email Reader - set Canary Mail. See the attached screenshot.

iOS
You can set Canary as the default email client on your iOS via Device Settings > Canary > Default Mail App - Select Canary.

Android
You can set Canary as the default email client on Android via Device Settings > Default Apps > Email - Select Canary.
