An integrated threat protection solution designed to detect, investigate, and respond to cyber threats across Microsoft 365 services.
Hello, thank you for reaching out to Microsoft Q&A.
- What is the exact error message the sender receives when they try to email your address?
- Do you have a Personal or Work/School account?
Send a test email from another account of yours to the problematic email address. If you receive any bounce-back error message, please share the error message here.
Meanwhile, check if you have enough storage space to send or receive emails.
With a Microsoft account, you get 5GB of OneDrive Cloud Storage and 15Gb of Outlook email storage. If you exceed any one of the limits, you won't be able to send or receive emails in your Outlook account.
https://outlook.live.com/mail/0/options/accounts-category/storage
Sign in to your Microsoft account using the link above.
Check whether you have enough storage.