Email suppression on hard bounces

[arunmr1980]

Implement email suppression for hard bounces
- When hard bounce happens, we need to add that email to account level suppression list 

Resources

• Using the Amazon SES account-level suppression list : https://docs.aws.amazon.com/ses/latest/dg/sending-email-suppression-list.html

• Handling high bounce rates. https://aws.amazon.com/premiumsupport/knowledge-center/ses-high-bounce-rate/

• Simulators for various email conditions https://docs.aws.amazon.com/ses/latest/dg/send-an-email-from-console.html

• SAM template for SNS lambda subscription https://medium.com/build-succeeded/subscribe-an-aws-lambda-function-to-an-sns-topic-in-cloudformation-and-work-6997a0f0b59b

[arunmr1980]

Implementation

1. Setup SES bounce notifications using a SNS topic (https://aws.amazon.com/premiumsupport/knowledge-center/ses-bounce-notifications-sns/)
2. Add a lambda trigger to the SNS topic that receive notifications
3. Add the emails to account level suppression list (https://docs.aws.amazon.com/ses/latest/dg/sending-email-suppression-list.html)

[arunmr1980]

Setting up SNS bounce notifications for SES

• Open the Amazon SES console.
• In the navigation pane, choose Domains or Email Addresses. Then, select the verified domain or email address that you want to get bounce notifications for.
• Expand Notifications, and then choose Edit Configuration.
• Under SNS Topic Configuration, for Bounces, select the SNS topic that you created.
• Note: You can choose to also enable notifications for Complaints and Deliveries. You can publish multiple event types to the same SNS topic or to different SNS topics.
• Select Include original headers if you want the Amazon SNS notifications to contain the original headers of the emails that you send using Amazon SES.
• Choose Save Config.

[arunmr1980]

Test the bounce notifications using the Amazon SES mailbox simulator (https://docs.aws.amazon.com/ses/latest/DeveloperGuide/send-email-simulator.html)

• Open the Amazon SES console.
• In the navigation pane, choose Domains or Email Addresses. Then, select the verified domain or email address that you want to set up bounce notifications for.
• Choose Send a Test Email.
• In the test email form, for the To field, enter bounce@simulator.amazonses.com. Then, complete the rest of the form with the values that you want for the test email.
• Choose Send Test Email.
• Open the inbox for the email address that you set as the endpoint of the SNS topic. Confirm that you have an email with the subject line AWS Notification Message that contains the bounce notification.

[arunmr1980]

SNS to Lambda integration in SAM template :- Invoke failure

https://medium.com/build-succeeded/subscribe-an-aws-lambda-function-to-an-sns-topic-in-cloudformation-and-work-6997a0f0b59b

[arunmr1980]

Successful response on sending email to suppression list

[INFO] 2022-04-19T05:45:41.527Z c7e36171-bb15-42ac-8b2f-ccb27b0f801a {'ResponseMetadata': {'RequestId': '5d16a70e-8711-4c88-af64-2ca267f08c65', 'HTTPStatusCode': 200, 'HTTPHeaders': {'date': 'Tue, 19 Apr 2022 05:45:41 GMT', 'content-type': 'application/json', 'content-length': '2', 'connection': 'keep-alive', 'x-amzn-requestid': '5d16a70e-8711-4c88-af64-2ca267f08c65'}, 'RetryAttempts': 0}} | [INFO] 2022-04-19T05:45:41.527Z c7e36171-bb15-42ac-8b2f-ccb27b0f801a {'ResponseMetadata': {'RequestId': '5d16a70e-8711-4c88-af64-2ca267f08c65', 'HTTPStatusCode': 200, 'HTTPHeaders': {'date': 'Tue, 19 Apr 2022 05:45:41 GMT', 'content-type': 'application/json', 'content-length': '2', 'connection': 'keep-alive', 'x-amzn-requestid': '5d16a70e-8711-4c88-af64-2ca267f08c65'}, 'RetryAttempts': 0}}

[arunmr1980]

Does emails in in suppression list still result in bounce?

Yes, This seem to result in a bounce though it does not count against accounts bounce rate.

According to this knowledge center article, the following error message is supposed to show

"Amazon SES did not send the message to this address because it is on the suppression list for your account. For more information about removing addresses from the suppression list, see the Amazon SES Developer Guide at https://docs.aws.amazon.com/ses/latest/DeveloperGuide/sending-email-suppression-list.html"

However this does not happen on testing. Documentation in other places seem to suggest that email to suppressed email ids is a successful send event. So an error is not expected.

Documentation regarding account level suppression list mention the following.

If you attempt to send a message to an address that's on your account-level suppression list, SES accepts the message, but doesn't send it.

Documentation regarding monitoring emails define send event as follows.

Send – The send request was successful and Amazon SES will attempt to deliver the message to the recipient’s mail server. (If account-level or global suppression is being used, SES will still count it as a send, but delivery is suppressed.)

boto3 documentation does not have a message field in its response.