Your notification email is the email which receives all updates from Cosmos. Changing your notification email does not change your account email and has no impact on how you sign in to Cosmos.
How to change your notification email
To protect privacy and security, any new notification email must be verified within 24 hours. Only verified addresses will receive notifications, keeping sensitive information from being misdelivered.
Go to Settings > Notifications, then click Change email.
Enter your new, valid email and click Send verification email.
Check your inbox and confirm your new notification email via the button in the verification email. You’ll be redirected to see if verification succeeded (you can always resend if needed).