Hello, thank you for reaching out to Microsoft Q&A.
Maybe you accidentally selected all emails in your inbox and moved them to Junk, or perhaps you created a rule that automatically moves all inbox emails to the Junk folder?
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Open an incognito tab and sign in with your Microsoft account on Outlook.com online.
Go to the Junk email folder.
If you see the emails you wanted to reach them with in your inbox, but they ended up in the Junk folder, select those emails in the list and click 'Move them to inbox'.
Alternatively, go to Outlook email settings > Select Mail > Rules.
If you have added any rule that moves emails to your Junk email folder, delete the rule.
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Then, go to Mail > Junk email > Blocked senders and domains.
If the email address is in the Blocked sender's lists, remove it from the lists and add it to the safe sender's lists.
Let me know if you still need more help.