command="sendemail", [Errno -2] Name or service not known while sending mail to xxx@gmail.com

[timyong80]

Hello everyone,

Does anyone know what the above error message means when using the sendemail function? I've googled it but there were no results. Alert email works fine but not sendemail.

FYI, this error occurred on Splunk Cloud. I've seen a similar error below in Splunk on-prem (solved by adjusting some roles to the account) but this is a new error that I've encountered. 

[map]: command="sendemail", 'rootCAPath' while sending mail to: xxx@gmail.com

It appears that the sendemail function is not configured or installed in this Splunk Cloud instance. Is there any steps that needs to be configured by the admin (sendemail.py, etc)? I supposed the configurations should be the same as in Splunk on-prem? If yes, would appreciate your advice so that I can let my admin know.  

Thank you.

[Joe_Hartzel]

If you're encountering the error command="sendemail", [Errno -2] Name or service not known in Splunk, it typically indicates a DNS resolution issue where the SMTP server's hostname cannot be resolved. Here's how to troubleshoot and resolve this:

1. Verify SMTP Server Hostname

Ensure that the SMTP server hostname specified in your Splunk configuration is correct. This should be a fully qualified domain name (FQDN) that can be resolved by your system's DNS. For example:

smtp.example.com

Avoid using IP addresses directly in the configuration, as they may not be resolvable in all contexts.

2. Check DNS Resolution

From the Splunk instance, test if the SMTP server's hostname can be resolved:

nslookup smtp.example.com

If this command fails, it indicates a DNS issue. Ensure that your Splunk server has proper DNS settings and can reach the DNS server.

3. Test SMTP Server Connectivity

Verify that your Splunk instance can reach the SMTP server on the required port (typically port 25, 465, or 587):

telnet smtp.example.com 25

If the connection is refused or times out, check your firewall settings and ensure that the SMTP server is accessible from your Splunk instance.

4. Configure SMTP Settings in Splunk

Ensure that your SMTP settings are correctly configured in Splunk:

Navigate to Settings > Server settings > Email settings.

Enter the correct SMTP server hostname and port.

Provide authentication details if required (username and password).

Specify the sender email address.

5. Check for Firewall or Proxy Issues

If your Splunk instance is behind a firewall or proxy, ensure that it allows outbound connections to the SMTP server on the necessary ports. You may need to configure proxy settings in Splunk if applicable.

6. Review Splunk Logs

Check Splunk's internal logs for more detailed error messages:

$SPLUNK_HOME/var/log/splunk/splunkd.log

Look for entries related to the sendemail command to identify any additional issues.

7. Restart Splunk

After making changes to the configuration, restart Splunk to apply the new settings:

$SPLUNK_HOME/bin/splunk restart

By following these steps, you should be able to resolve the [Errno -2] Name or service not known error and successfully send emails from Splunk. If the issue persists, consider reaching out to your network administrator to ensure proper DNS and network configurations.