Hi twl1582,
Perform a clean boot to check.
https://support.microsoft.com/en-sg/help/929135/how-to-perform-a-clean-boot-in-windows
You could go to the Cortana setting and uncheck the e-mail option.
Type “Cortana Setting” in the Search Bar and find “Talk to Cortana”. Then uncheck “Let Cortana access my calendar, email, messages, and Power BI data when my
device is locked”.
Also try to set Mail App as you default program to check.
Please follow the steps give below to set Mail App as you default program.
a) Press Windows Key + X key.
b) Select Control Panel. Click on Default Programs.
c) Click on Set your default programs.
d) Click on the Mail app from the list on the left hand side.
e) Click on Set this program as default.
f) Click on OK.
Hope it will be helpful to you
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