Troubleshooting Tip: How to troubleshoot Email Server configuration error 'Authentication Failed: Invalid username or password' in FortiSIEM

[kdave]

Description	This article describes how to troubleshoot Email Server configuration error 'Authentication Failed: Invalid username or password' in FortiSIEM.
Scope	FortiSIEM.
Solution	While configuring Email Server in FortiSIEM under Admin -> Settings -> System -> Email, the following error is observed after entering correct Username/password, Email Server IP/URL and port details. Authentication failed: Invalid username or password AppSvr logs shows exact errors while checking logs as below. tail -f /opt/glassfish/domains/domain1/logs/phoenix.log 2025-11-17 15:04:32,081 [p: thread-pool-1; w: 59] ERROR com.ph.phoenix.service.notify.email.SmtpClientHelper - [PH_APPSERVER_NOTIFIER_ERROR]:[eventSeverity]=PHL_ERROR,[phEventCategory]=3,[procName]=AppServer,[phCustId]=0,[phLogDetail]=AuthenticationFailedException: 535 5.7.3 Authentication unsuccessful [MA5PR01CA0128.INDPRD01.PROD.OUTLOOK.COM 2025-11-17T09:34:49.124Z 08DE2522D0FE77B3] tail -f /opt/glassfish/domains/domain1/logs/server.log Note down the exception AuthenticationFailedException: 535 5.7.3 Authentication unsuccessful This exception describes that SMTP Authentication may be disabled from Email Server for security reasons even though Username/Password is correct. Email Service providers such as Gmail/Microsoft Office365 disable SMTP authentication from other applications such as FortiSIEM. SMTP Authentication and related configuration needs to be enabled from Email Server to resolve such errors. Once the necessary configuration changes have been applied from Email server, Email Server configuration can be tested and saved successfully. Related document: Email Settings - FortiSIEM user guide