AWS SMS NOT Delivered Despite Success Response - amazon-web-services

Question

I have seen the posts on StackOverflow with similar issues as mine, but none of them helped me resolve the issue. This is why I am creating a new post.
When I first set AWS SNS up, I tested sending SMS using the online console, it worked!
Then I wrote PHP code to send a sample message. I got some errors but was able to resolve them easily. However, when I got a success response, the message was not received at all.
I thought it is a Limitation issue. So I contacted AWS and increased my limit to 20US/month. I updated the preferences, but still the same result. I get a success response, the dashboard shows that a message was sent successfully (although it takes time to update the number of messages sent). But the message is not received.
Here is my code for reference:
<?php
require './aws/aws-autoloader.php';
use Aws\Sns\SnsClient;
use Aws\Exception\AwsException;
$sdk = new SnsClient([
'region' => 'us-east-1',
'version' => 'latest',
'credentials' => [
'key' => 'XXXXXXXXXXXXXXXXXXX',
'secret' => 'XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX'
]
]);
try {
$result = $sdk->publish([
'Message' => 'Reminder - You are scheduled for a session on 2020-05-20 at 4:30 PM',
'MessageStructure' => 'String',
'PhoneNumber' => '+1XXX789XXXX',
'MessageAttributes' => [
'AWS.SNS.SMS.SenderID' => [
'DataType' => 'String',
'StringValue' => 'MyName'
],
'AWS.SNS.SMS.SMSType' => [
'DataType' => 'String',
'StringValue' => 'Transactional'
]
]
]);
var_dump($result);
echo "\n";
} catch (AwsException $e) {
// output error message if fails
var_dump($e->getMessage());
}
And here is the result object:
object(Aws\Result)#119 (2) {
["data":"Aws\Result":private]=>
array(2) {
["MessageId"]=>
string(36) "8cf11950-cdb0-5503-9b69-4e6e9b61eaba"
["#metadata"]=>
array(4) {
["statusCode"]=>
int(200)
["effectiveUri"]=>
string(35) "https://sns.us-east-1.amazonaws.com"
["headers"]=>
array(4) {
["x-amzn-requestid"]=>
string(36) "0488b803-8776-57bc-b9a9-ef3dd1a71805"
["content-type"]=>
string(8) "text/xml"
["content-length"]=>
string(3) "294"
["date"]=>
string(29) "Tue, 19 May 2020 21:50:09 GMT"
}
["transferStats"]=>
array(1) {
["http"]=>
array(1) {
[0]=>
array(0) {
}
}
}
}
}
["monitoringEvents":"Aws\Result":private]=>
array(0) {
}
}
I am out of ideas. Not sure how to resolve this issue. Any help would be appreciated.
Thanks,

Answer 1

I believe by SMS's nature it can fail from time to time.
By my own observation, AWS employ some regional SMS providers that will help them send the SMS to your carriers.
Sometimes the SMS provider fails to send. Sometimes they are rejected by the receiving carrier.
At the moment, we have no way to be sure if It fails ( and react on this situation ) If the SMS is critical to your business, I suggest using another SMS service in conjunction with AWS.