AWS SNS SMS for Etihad Etisalat (Mobily) provider is always failing

For successful SMS delivery to Saudi Arabia, you'll need to either use a registered long code or a registered sender ID. The registration of the sender ID is a requirement to ensure reliable SMS delivery to Saudi Arabian phone numbers. You can find more details on the sender ID registration process in the Pinpoint documentation [+].

If you opt to use a registered sender ID, be mindful that the registration is case-sensitive. Ensure that you correctly use the exact letter case as specified in your sender ID registration.

[+] Saudi Arabia sender ID registration in AWS End User Messaging SMS - https://docs.aws.amazon.com/sms-voice/latest/userguide/registrations-saudi-arabia.html

The issue you're experiencing with AWS SNS SMS failing specifically for Etihad Etisalat (Mobily) provider, while working for other numbers, could be due to several factors:

1. Carrier-specific restrictions: Mobily may have implemented specific filtering mechanisms or security policies that are preventing the delivery of SMS messages from AWS SNS.

2. Network issues: There could be temporary network problems or routing issues between AWS and Mobily's infrastructure.

3. Sender ID registration: Some countries and carriers require sender IDs to be registered. It's possible that your sender ID is not properly registered or recognized by Mobily.

4. Message content: The content of your messages might be triggering spam filters specifically on Mobily's network.

5. Regional settings: Ensure that you're using an AWS region that fully supports SMS messaging for your destination country.

To troubleshoot this issue:

1. Contact Mobily directly to inquire about any restrictions or requirements for receiving SMS messages from cloud services like AWS SNS.

2. Verify if there are any specific sender ID registration requirements for Mobily in your country.

3. Review your message content to ensure it complies with all carrier guidelines.

4. Enable and analyze Amazon CloudWatch Logs for your SMS messages to get more detailed information about the delivery attempts and any potential issues specific to Mobily numbers.

5. Try sending messages with different content or from different AWS regions to see if it affects the delivery.

6. If the problem persists, consider opening a support ticket with AWS. They may be able to provide more specific insights or work with their SMS providers to identify any issues in message routing to Mobily.

Remember, even though AWS shows the SMS as sent successfully, the final delivery depends on the receiving carrier's systems and policies. The "Phone is currently unreachable/unavailable" status could be due to how Mobily handles and reports message statuses back to AWS.
Sources
AWS shows that the SMS was sent successfully, but the user did not receive it | AWS re:Post
AWS SNS can not send SMS to mobile phone | AWS re:Post