Managing the Suppression List

Learn about managing the suppression list using the Email Delivery service. You can add or remove an email address from the suppression list.

A suppressed email is an address to which an email was sent and resulted in either a hard bounce or a complaint.

As a result, the address cannot be used to send emails and is added to the user’s suppression list. If the sender has enabled logging, the exact reason for the initial hard bounce can be found through public logging in the OCI Console. For more information, see Using the Console.

If you have not set up service logs, configure them first, and then remove the suppression. If the problem persists, you can see the error in your logs the next time you attempt to send an email to the suppressed email.

Common examples of hard bounces include either a misspelled email address or an invalid address as a result of someone leaving a company, changing email providers, and so on. Another example is when a distribution list or email alias has an invalid recipient in which case the entire email alias is suppressed. The correct action in the latter case is to remove the invalid recipient from the alias and then remove the distribution list or email alias from the suppression list.

Another example is where the receiving mail server has a bug or is otherwise misconfigured, and a valid recipient returns an error. If you’ve verified this is the case, you can remove the suppression.

We highly recommend that you don’t send emails to suppressed email addresses before the reason for their initial hard bounce is figured out. In rare cases, like a distribution list where a single bad address can affect the whole list, an address can be removed and used to send emails again. Hard-bounced addresses such as incorrectly spelled email addresses or spam complaints should never be remailed to as the negatives (potential IP or domain blocklisting) far outweigh any positives.

The suppression mechanism is critical to protect the reputation of all emails from this service as repeated attempts to send to an invalid recipient results in the sender being considered a spammer by various anti-spam technologies. As a result, you can’t opt out from the suppression mechanism.

Best practice to avoid suppression:
  • Ensure that the sending domain has a valid DKIM, so that the recipient domain's postmaster doesn’t block the mails.
  • If you use DL (Distribution list), ensure that invalid or incorrect email addresses aren’t part of the DL before sending emails again to the DL.

As you begin to send email, Email Delivery automatically adds email addresses with bounce codes showing permanent failures, or user complaints to the suppression list to protect your sender reputation. Email Delivery doesn’t send any messages to these recipients in the future. Reasons for suppression currently include:

  • Complaints
  • Hard bounces
  • Repetitive soft bounces
  • Manual entries
  • List-unsubscribe requests

Manually add an email address to the suppression list to prevent it from being part of your sending list. Users must setup SPF and DKIM to help recipient email addresses from being automatically added to the suppression list in most of the cases. For more information, see Configuring SPF and Using the Console.

Users are required to have correct permissions to manage the suppression list. Currently, identity policies for suppression must be at the tenant level (not at the compartment level). The following is an example of the permission policy statement.

Allow group <sender admins group> to manage suppressions in tenancy

Suppressions are stored at the tenancy level. Therefore, any request requiring a compartmentId must provide the tenancyId as the compartmentId. For example:

Allow group <ordinary users group> to inspect suppressions in tenancy
Allow group <power users group> to read suppressions in tenancy
Allow group <sender admins group> to manage suppressions in tenancy

For other policies required for Email sending, see Managing Approved Senders and Create SMTP Credentials. Also, for advanced policies, see Advanced Policy Features.

You can perform the following suppression list management tasks: