Using SNS vs AWS End User Messaging SMS for sending SMS messages

Regarding your questions about SNS and AWS End User Messaging SMS:

1. Yes, when you send SMS messages through Amazon SNS, you do benefit from AWS End User Messaging SMS features. The integration between these services allows you to access features like phone pools, configuration sets, and other capabilities such as two-way messaging, granular resource permissions, and country block rules. This integration happened without requiring any changes to existing configurations, so SNS customers can leverage these enhanced capabilities automatically.

2. There are valid reasons to consider both approaches:

Using SNS for SMS delivery provides the benefit of the pub/sub model with its built-in retry logic and failure handling. It's particularly useful when you need to send the same message to multiple recipients or want to integrate with other AWS services through the SNS topic-subscription model.

Using AWS End User Messaging SMS directly might be preferable when you need specific SMS capabilities like:

• Two-way SMS messaging (receiving messages from customers)
• Multi-media messaging (MMS)
• Using the SMS simulator for testing
• More granular control over SMS resources
• Number fail-over with phone pools

The choice depends on your specific use case. If you need the pub/sub model with retry logic, SNS is advantageous. If you need more specialized SMS features and direct control over the messaging process, using AWS End User Messaging SMS directly might be more appropriate.

Note that billing for SMS messages sent through either service is now consolidated through AWS End User Messaging SMS, allowing you to manage your SMS spending in one place.
Sources
Mobile text messaging with Amazon SNS - Amazon Simple Notification Service
Amazon SNS now delivers SMS text messages via AWS End User Messaging - AWS
Front-end web & mobile services - Amazon Simple Notification Service
Best practices for Amazon SNS SMS messaging - Amazon Simple Notification Service