Issue with the opendistro Elasticsearch alerting

Hello Team,

I am using opendistro for elasticsearch 7.10.2 version ,the alerting plugin version ,i have configured the mail sender with 465 SSL port to one of domain,

The all above setup i have installed and running on one of Azure Ubuntu VM instance,so here the issue is when configured after sending test email from alerting in kibana UI ,unable to get receive the test email from the configured sender.

Please provide the information

what is causing the issue for this email alerting blocking here.

Thanks ,

WhatsApp Image 2021-11-11 at 14.58.37