Sending email notifications in Amazon OpenSearch

You're correct that Amazon OpenSearch Service requires version 2.3 or later to use the Notifications feature, but there seems to be some confusion about the versioning. OpenSearch 2.19 is indeed a valid version and is newer than 2.3, so you should be able to use the Notifications feature with your domain.

For sending email notifications from Amazon OpenSearch Service, the recommended approach is to use Amazon SNS as a notification channel, which can then be integrated with Amazon SES for email delivery. Direct SMTP email sending is not available in AWS OpenSearch implementation.

Here's how to set up email notifications:

1. Configure Amazon SES to handle the email sending
2. Set up an Amazon SNS topic and create an email subscription with your email address
3. Confirm the subscription via the email you receive
4. In OpenSearch Dashboards, go to Notifications, then Channels, and create a new channel
5. Select Amazon SNS as the channel type
6. Configure the necessary IAM permissions for OpenSearch to use Amazon SNS
7. Create monitors and alerts in OpenSearch that use this notification channel

If you're still experiencing issues, verify that:

• Your domain is running OpenSearch 2.3 or later
• You've properly configured the IAM permissions for OpenSearch to access SNS
• Your SNS subscription is confirmed
• The alerting conditions are being triggered

Remember that starting with OpenSearch version 2.0, notification channels replaced alerting destinations, and in version 2.3 and later, existing destinations are automatically migrated to notification channels.
Sources
AWS Opensearch Email Sender for Notification | AWS re:Post
Configuring alerts in Amazon OpenSearch Service - Amazon OpenSearch Service
AOSOPS03-BP02 Configure notification services to receive monitoring alerts - Amazon OpenSearch Service Lens