AWS is sending complaints for all emails sent through SES all of a sudden

<<Apologies for long verbiage>>

I’ve also faced this issue in one of my personal account, where I got this email:

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DETAILS

Your current bounce rate is X%. We measured this rate over the last X eligible emails* you sent. Our analysis covers the last X days.

We recommend that you maintain a bounce rate below 5%. If your bounce rate exceeds 10%, we might pause your ability to send additional email.

The bounce rate is based on the number of hard bounces that occur as a result of the emails you send. A hard bounce occurs when an email address doesn't exist.

Email providers interpret a high bounce rate as a sign that you're not actively managing your customer database, or that you're sending unsolicited email. Email providers might block your email if your bounce rate is too high. To protect your reputation as a sender, we monitor this metric closely and take action if the rate gets too high.

For more information about what to do if your account is under review or your account's ability to send email is paused, see our Enforcement FAQ at https://docs.aws.amazon.com/ses/latest/dg/faqs-enforcement.html. You can also use the Enforcement Dashboard to monitor the bounce and complaint rates for your account. For more information, see https://docs.aws.amazon.com/ses/latest/DeveloperGuide/monitor-sender-reputation.html.

If you're testing your system's ability to process bounce or complaint events, you should use the Amazon SES mailbox simulator. You can send email to the mailbox simulator without impacting the reputation metrics for your account. For more information, see https://docs.aws.amazon.com/ses/latest/dg/send-an-email-from-console.html.

*The number of eligible emails is based on the number of recipients, rather than the number of messages. For example, we count an email with 30 recipients on the BCC: line as 30 eligible emails.

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WHAT HAPPENS NEXT

If we don't hear back from you or if the problem hasn't been resolved within the next X emails you send, we'll pause your ability to send email using Amazon SES in order to protect your reputation as a sender.

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WHAT YOU CAN DO

First, you should have a system in place for monitoring bounces and complaints. When you receive a bounce notification, you should immediately stop sending email to the address that resulted in the bounce or complaint, and ensure that you don't attempt to contact that address again in the future. We recommend you manage your reputation by using the following SES features:

• Enable account-level suppression list to prevent repeat bounces and complaints from email addresses that have exhibited a history of bounces and complaints for your account. See https://docs.aws.amazon.com/ses/latest/dg/sending-email-suppression-list.html
• Enable Virtual Deliverability Manager for insights into your email sending success metrics, with drill-downs available for your email sending identities, configuration sets, and recipient ISPs. These insights can help you with subsequent remediation steps. See https://docs.aws.amazon.com/ses/latest/dg/vdm.html
• Note that using the Virtual Deliverability Manager will result in additional charges to your account, as per https://aws.amazon.com/ses/pricing/ While we strongly recommend implementing the above SES reputation management features, you can, however, manage bounces and complaints on your own. If you do, we recommend that you start by reviewing our best practices https://docs.aws.amazon.com/ses/latest/dg/best-practices.html and choose between event publishing https://docs.aws.amazon.com/ses/latest/dg/monitor-using-event-publishing.html (recommended) and email identity notifications https://docs.aws.amazon.com/ses/latest/dg/monitor-sending-activity-using-notifications.html for ingesting and processing email sending events.

Second, use the bounce information that you collect to analyze your email-sending practices and determine what caused the bounces. For example, how did you collect the email addresses that you're contacting? Did you collect the addresses by using a web form that could be exploited? Are you sending test emails to fictitious addresses? Identifying the causes of these bounces can help you determine which changes to implement. You can reply to this message to request a small sample of recent messages that resulted in bounces.

Third, make changes to your sending processes or procedures based on your analysis of the issue. Implement these changes fully before you proceed to the next step.

Finally, contact us with answers to the following questions:

• What caused your high bounce rate?
• What changes have you made in your email-sending systems or processes?
• How do these changes ensure that the issue won't occur again in the future? We'll evaluate your responses to these questions. If we agree that your changes address this issue, we'll reset the metrics for your account, and end your review period or restore your account's ability to send email.

Important: After we end your review period or restore your account's ability to send email, you still have to keep your bounce rate at an acceptable level. If the bounce rate gets too high, we'll place your account under review, or pause your ability to send email again. If your bounce rate repeatedly exceeds these limits, we'll permanently suspend your account's ability to send email using SES.

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I added a monitoring mechanism for bounce rate and informed about this change then restriction was lifted.

Also, take a look at this re:Post Thread.

Hope this may give you some insight.

Abhishek