Microsoft365 Cannot Send Email | 550 5.1.8 Access DeniedMicrosoft365 Cannot Send Email | 550 5.1.8 Access Denied
- -go to: https://admin.microsoft.com/
- -click SECURITY ADMIN CENTER
- -click ALERTS > DASHBOARD (on the left-hand side).
- -click RESTRICTED-USERS (on the right-hand side).
- (or just go here: https://protection.office.com/restrictedusers)
- -you will see the restricted users and why they are restricted.
- -if needed, UNBLOCK by checkmark and click UNBLOCK (at the top).
To see the policy that triggered this:
- - go here: https://protection.office.com/antispam
- -click Anti-spam outbound policy (Default).
- -click EDIT-PROTECTION.
- -change to NO-ACTION, ALERT-ONLY (note that this is NOT RECOMMENDED).
- -or keep the default of RESTRICT-THE-USER-FROM-SENDING-MAIL-UNTIL-THE-FOLLOWING-DAY
To see the emails that went out in the last 24 hours:
- -go here: https://admin.exchange.microsoft.com/#/messagetrace
- -click MESSAGES-SENT-FROM-MY-PRIMARY-DOMAIN-IN-THE-LAST-DAY
- -click SEARCH
- -a list of messages sent will show. Inspect to see/find the culprit.