Why did I get an email from AWS stating that my Amazon SNS subscription was manually disabled?

Last updated: 2019-11-25

I recently received an email from AWS saying that one of my Amazon Simple Notification Service (Amazon SNS) email subscriptions was manually disabled. Why was my subscription disabled?

Short Description

If you get this email, you likely published messages at a high rate to an SNS topic that contained an email subscription. Amazon SNS supports an email message delivery rate of 10 transactions per second (TPS) to SNS topics, per AWS account.

If messages are published to an SNS topic in your AWS account at a higher TPS, Amazon SNS disables your subscription to:

  • Prevent spamming the destination inbox with events.
  • Protect the recipient mail server from being flooded with messages.
  • Avoid Internet Service Providers (ISPs) identifying elevated traffic as spam and blocking messages from delivery.

Resolution

To prevent this from occurring again, it's a best practice that you avoid subscribing email addresses to high-volume SNS topics. Commonly accepted use cases for SNS topic email subscriptions include monitoring Amazon CloudWatch alarms and sending usage reports to multiple email addresses.

For high-volume SNS topics, it's a best practice to subscribe only high-throughput, system-to-system endpoints instead, such as Amazon Simple Queue Service (Amazon SQS) queues, AWS Lambda functions, and HTTP endpoints. These types of subscriptions support a much higher TPS.