I cannot send out emails and receive this message when I try - Microsoft Community

your message couldn't delivered because weren't recognized valid sender. common reason email address suspected of sending spam , it's no longer allowed send messages outside of organization. contact email admin assistance.

hi margaret,

based on error message, sender seems blocked sending emails. suggest involve admin remove block on sender following article below:

https://technet.microsoft.com/en-us/library/dn458545(v=exchg.150).aspx

if doesn’t work you, i’d collect tenant information , entire ndr via private message , involve relevant team fix issue. if not office 365 admin, please let admin check information. can click link below access private message.

https://answers.microsoft.com/en-us/privatemessages/list


regards,
yang

Office / Outlook / Other/unknown / Office 365 for business