Suppression lists prevent sending emails to email addresses that have opted out, filed an abuse complaint, or are no longer valid (bad email address).

Acoustic Campaign automates suppression at the organization level by creating a master suppression list and automatically adding contacts to it. In addition, you can create your own suppression list.

About suppression lists

When a contact unsubscribes from a database, the contact is added to the database suppression list and their status on the Suppression List Summary page shows as opted-in because they have opted into the suppression list. This opt-in date shows when the contact unsubscribed from the email list.

Suppression can also occur for other reasons, such as an address containing a domain or prefix that is on the email blocking list (in Acoustic Campaign, go to Settings > Email blocking) or an address that is on the global suppression list (clients do not have access to this list).

While a contact's email address is on an organization-level master suppression list, he or she will not receive email from any database in the organization. If a contact's email address is on a database-level suppression list, he or she will not receive email from that particular database.

Note: By default, your organization contains an organization-level suppression list, called the master suppression list.

You cannot add a field to a suppression list. Unlike a regular database, a suppression list only stores email addresses. Other than system fields, only the email field is included. No other field can be added.

Organization impacts

The master suppression list in its default setting collects all abuse complaints, undeliverables (invalid mailboxes), and opt-outs from any email sent using any database in the organization. These addresses are then excluded from any email going out of the organization.

The opt-outs and abuse complaints for an email are also flagged (as opted out) on the database used to send that email. The two most common requests for suppression settings are detailed below:

• To keep opt-outs separate for each database.
• To replace the organization-level suppression list.

Permissions are set so you cannot perform these requests without contacting support. This is to prevent you from accidentally making changes to these settings that could negatively impact your deliverability.

Types of suppression lists in Acoustic Campaign

The different types of suppression lists are:

• Organization level
• Database level (list level)
• Email level
• MD5 encrypted

Organization-level suppression

Only allows the user to select suppression list as the database/list type.

Maintains all abuse complaints, undeliverables, and opt-outs on a single master suppression list. This suppresses these addresses from all emails sent out of this organization. This is the default setting for all organizations.

Organizations can create and use multiple suppression lists; however, only one organization-level suppression list can be active at a time.

If you choose to maintain opt-outs on an organizational level, a contact who opts out of an email sent to any database is added to an organization-level suppression list. This is typically referred to as the master suppression list, and is suppressed on subsequent emails to any database within the same organization. The suppression happens at send time when Acoustic Campaign is determining which contacts should receive a given email.

Most Acoustic Campaign organizations must use organization-level suppression, to remain compliant with ISPs (AOL, Yahoo, and Gmail) terms of service. ISPs track abuse complaints against client's individual IP address, not a given database. Since most Acoustic Campaign organizations only have a single IP address associated with them, we must suppress these addresses from all emails coming out of an organization. The master suppression list also collects undeliverable and opt-out addresses. This helps to ensure proper database management best practices, which keeps your sends free of invalid addresses and opt-outs.

However, some clients wish to keep opt-outs separate for each database. Contact support if you wish to request that your organization's suppression list settings are changed to 'Do Not Add Opt-Outs'.

Database-level suppression

Database-level suppression maintains all abuse complaints, undeliverables, and opt-outs on separate suppression lists assigned to each individual database in an organization. This suppresses these addresses from all emails sent, using the database with which the suppression list is associated. This is not a commonly used configuration.

Note: These suppression lists are not created by default and must be created by the user.

Note: Acoustic Campaign consults the master suppression list first and then any list level suppression that is set up. So both suppression lists are applied.

If you choose to maintain opt-outs on a database level, a contact who opts out of an email sent to a specific database is marked as opted out on that database only, and is suppressed (not sent to) on subsequent emails to the same database. Again, the suppression happens at send time when Acoustic Campaign is determining which contacts should receive an email. They continue to receive emails sent to all other databases.

Due to the suppression requirements outlined above, clients can use list-level suppression only if they have an IP address for each separate database. ISPs track abuse complaints against an individual IP address. As a result, an IP address cannot be shared among multiple databases. This prevents clients from re-sending emails to contacts who filed an abuse compliant against the IP address. This configuration is not common. Most of our clients use the organization-level suppression, as noted above.

Email-level suppression

Applied at send time for a specific email. Unlike organization level and database level suppression lists, contacts are not added to this list upon opt-out. Email-level suppression lists are intended to add additional suppression to an email. If a contact opts out of the list, they are marked as opted out and added to the organization suppression list or database level suppression list if activated.

MD5-encrypted suppression

MD5-encrypted suppression lists provide an added layer of security if you are transferring your suppression list to another company and you don't want them to be able to send to it. MD5-encrypted lists are used by organizations or agencies that send emails for third parties, such as an organization that sends medical information on behalf of a health care system.

In compliance with the recommendation from the Email Sender and Provider Coalition (ESPC), organizations can now import, export, and use MD5-encrypted suppression lists within Acoustic Campaign. However, MD5 encryption can only be selected when creating a suppression list in an initial import.

When you are importing data into a new suppression list, select the The import file specified contains MD5 hash coded email addresses check box. After the import is complete and the new suppression list is created, future imports will also allow and require the MD5 format.

Import an MD5-encryped suppression list

Create a new contact source that is MD5-enabled. Then, import the MD5 encrypted contacts into that list by performing a new import into a suppression list. Once this is done, the import file specified will contain MD5 hash encoded email addresses. All future addresses added to this suppression list will also be encoded. If your MD5 suppression list already exists, you will do an Import Update to get the data.

Using suppression lists in queries

It is not possible to create a query based off the master suppression list. However, the master suppression list can be exported, re-imported as a database, and then a query is able to be created from the database.

Create a suppression list

Add a suppression list to a database

When you add a suppression list to a database, whenever an email is sent to that database, contacts are checked against the associated suppression list and against your organization's master suppression list.

1. Go to Data.
2. Click into the chosen database.
3. On the Fields tab, click Settings.
4. On the Settings tab, ensure that the Enable Suppression List is checked.
5. Select the suppression list.
6. In the Suppression Opt-Out Handling field, you can decide whether opt-outs are added to the selected suppression list.
7. Click Save.

Suppression lists are attached to emails and programs at the database level.

Any emails sent to a contact source associated with the parent database will now use the suppression list you chose.

View a list of suppressed contacts

You can view suppressed contacts in the organization suppression list, global suppression list, local prefixes, domains, and system domains in the single email report.

1. Go to the Single Mailing Report.
2. Click the report name to open the Single Mailing Report page.
3. Select Suppressed Contacts from the Summary list.
4. Do either of the following:
   • Click Update.
   • Scroll to the Delivery Info section and click Suppressed.
5. Select the name of a suppressed list to view contact information, including the contact's email address and the date the contact was added to the suppression list.

Also see Suppression codes and descriptions.

View the suppression list included in an email

You can view a suppression list that is attached to an email to see who will not receive your email.

1. Select Data.
2. Select the Suppression List tab.
3. Select the name of your suppression list.
4. Select the Email tab.

   A list of emails included in the selected suppression list opens. You can see the email status and the send or schedule date.

Find suppressed contacts before sending an email

You can see a snapshot of the number of contacts that were suppressed before the email is sent, due to IP warming, duplicate entries, frequency control, or email blocking.

To see this information, go to Select email or Open email draft. Alternatively, you can click the On to Send button on the top of your email template page.

You can also view a detailed report of contacts suppressed after the email was sent in the single mailing report.