Hello, thank you for reaching out to Microsoft Q&A.
Are you able to send emails?
Could you please share the exact error message the sender receives when they try to send an email to your account?
Send a test email from another one of your own accounts to the affected email address. Then check:
- Whether you receive any bounce-back (non-delivery) error messages, and the email gets stuck in the Outbox.
If you receive an error, please copy and paste the complete error message here.
In the meantime, please check your Microsoft e-mail forwarding rules and storage settings to confirm that you have enough space to send and receive email online:
- Go to https://outlook.live.com/mail/0/options/accounts-category/storage.
- Sign in with your Microsoft account.
- Verify that you have sufficient storage available to send and receive emails.
To check e-mail forwarding rules, see
https://outlook.live.com/mail/0/options/mail/forwarding
- If your emails are automatically forwarding to another address, click "Do not forward".
In addition, you should follow the steps here to keep your account safe and secure:
1. Reset your Microsoft account password.
Open an InPrivate/Incognito browser window and use the following link to reset your password: https://account.live.com/ResetPassword.aspx
2. Sign out of your account from all sessions.
Once the password reset is successful, sign in with your account here: https://account.live.com/proofs/Manage
Scroll down until you find Sign out everywhere. Select Sign out everywhere.
3. Enable two-step verification.
On the Security settings page, under Additional security, turn on Two-step verification. Make sure you have at least three security verification methods active.
After you have enabled these security protections, sign out of your account in the Outlook app and sign back in with your new password.