To make Trident the default email client:
Open Trident.
Go to Settings > General > Default Settings.
Click Go to Settings next to Set Trident as the default email app option.
In the Settings window that opens, search and select Trident under Set defaults for applications.
Under MAILTO, click the current default app, select Trident from the list of suggestions, and then click Set as default.
Go to Start > Settings > Apps > Default apps.
Under Set defaults for application, search for Trident and select it.
Click + Choose a default.
Under MAILTO, click the current default app, select Trident from the list of suggestions, and then click Set as default.
