My email <Mod remove PII> is receiving but not sending --I get error messages every tiem it wint send

Question

My email <Mod remove PII> is receiving but not sending --I get error messages every time it won't send:

"This message couldn't be delivered because the sending email address was not recognized as a valid sender. The most common reason for this error is that the email address is, or was, suspected of sending spam. Contact the organization's email admin for help and give them this error message."

HELP!

Answer 1

Hello Doug Teschner, thanks for posting this in our community.

It looks like this is a work or school account. Have you reached out to your IT admin? The error you’re seeing means the sending address is currently restricted by Microsoft’s outbound spam protection. This usually happens if the account was flagged for suspicious activity or sending patterns.

First, confirm your account security by changing your password immediately, enabling Multi-Factor Authentication (MFA), and checking for any unauthorized rules in Outlook or OWA by going to Settings, then Mail, then Rules and Forwarding.

Next, check if the account is restricted. Sign in to the Microsoft 365 Security & Compliance Center or ask your admin to do so. Navigate to Security & Compliance, then Threat Management, then Review, then Restricted Users. If your account is listed, select it and remove the restriction. See this article: What do you need to know before you begin?

After the restriction is removed, test sending from Outlook Web App (OWA). If you are still blocked, your admin should open a support ticket with Microsoft Partner Center or Microsoft 365 Support.

Kind regards,

John Oli