Root cause: After GDPR changes Atlassian made user emails private. By default these emails are private, but users can choose to share them with anyone. As your email address is also private QMetry couldn't access it to send the emails.
Solution : MMake below changes in your profile setting so that QMetry can send an email to you :
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User mentions in QMetry Test Asset’s text boxes such as Description, Comments, etc.
For further help contact QMetry Support.