Making Shift your default desktop email client will result in Shift being used to open any link in your browser associated with an email function. 

To make Shift your default desktop email client

1. Open your Options tray by hovering over the three dots in the left-hand corner of Shift

2. Click on 'Settings'

2. Go to 'General'

3. Click on 'Functionality'

4. Find 'Default email client' and select 'Set as Default'

5. Voila! You've successfully set Shift as your default email client 

If 'Set as Default' appears light gray then Shift is your default email client. 

To ensure that Shift is your default email client on a Mac OS please follow these steps: 

1. Open your Mail

2. Click on Mail in the top toolbar

3. Select 'Preferences'

4. Go to 'General'

5. Click on 'Default email reader' and select Shift from the drop down menu