Test Email Fails in Aria Operations for Networks Due to SMTP Port 25 Connectivity Issues

Products

• VCF Operations for Networks

Issue/Introduction

In Aria Operations for Networks (AON), a mail server was configured to send alert notifications via email. However, when attempting to send a test email, it fails with the error: “Failed to send test email.”

 

• Logs from the platform node reported the following error. Since any platform node in the cluster can be selected as the email sender, logs should be validated on all platform nodes.

Log location: logs/restapilayer/latest.log

YYYY-MM-DDT10:40:22.999Z ERROR vnera.components.EmailClient dw-5920280 - POST /infra/smtp-settings/send-test-email sendOnPrem:460 The email was not sent ('Test Email from VMware Aria Operations for Networks')
com.sun.mail.util.MailConnectException: Couldn't connect to host, port: X.X.X.X, 25_ timeout -1
at com.sun.mail.smtp.SMTPTransport.openServer(SMTPTransport.java:2118) _[javax.mail-1.5.6.jar:1.5.6]

• Connectivity validation confirmed that Platform2 and Platform3 could not reach the mail server on port 25, while Platform1 was able to connect successfully. The connectivity can be tested using the following command:

openssl s_client -connect <Email_Server_IP>:<port>

 

• Working example:

• Non-Working example:

Environment

VCF Aria Operations for Networks.

Cause

• During the test email attempt, Platform2 was automatically selected as the sender node in the AON cluster. It can choose anyone of the platform node in the cluster.
• Since Platform2 could not connect on port 25 to the mail server, the test email failed.
• The root cause was missing SMTP (port 25) connectivity from certain platform nodes to the mail server.

Resolution

To resolve this, engage your underlying network/security team to validate the following:

• Confirm that port 25 (SMTP) is open and reachable from all platform nodes (sources) in the AON cluster to the mail server (destination).
• Once port 25 connectivity is enabled across all nodes, the AON cluster will successfully send test and alert emails, regardless of which node is selected as the sender.