Hi Anna Tyrhaug,
Thank you for posting in the Microsoft Community Forums.
Open the email client you use frequently (e.g., Gmail, Outlook, Yahoo Mail, etc.).
Look for messages with your email address in your inbox or in Sent Messages. Messages you send or receive will usually show your full email address.
Log in to your email account through your email service provider's account.
Look for options like "Profile", "Settings", or "Account Information".
In these pages, you should be able to find the section that displays your email address.
Best regards
Neuvi Jiang