Jun 30 2019
- last edited on
Feb 07 2023
We are seeing SMTP ; 550 5.7.64 TenantAttribution; Relay Access Denied [OS2JPN01FT010.eop-JPN01.prod.protection.outlook.com]. while sending emails from relay using (Java program) tomcat server.
Jul 01 2019 10:17 AM
Literally the first result in search: https://docs.microsoft.com/en-us/exchange/troubleshoot/connectors/relay-access-denied-smtp
As detailed in the article, to relay messages via O365, you need a connector, verified either by a certificate or restricted to specific IP address.
Jul 25 2019 12:50 AM
@Vasil Michev Absolutely Correct, Best Answer