Suppression lists allow e-mail recipients to unsubscribe from messages sent from Dispatch for specific clients. Suppression lists are not global. When suppression lists are used in email communications a "unsubscribe" link is placed at the end of the message.

When a communication is generated, the members of the population are compared against the suppression list. If the member in the population is in the list of unsubscribed addresses, the member is marked as excluded from the communication and no message is sent.

End user experience

When a recipient clicks the "unsubscribe" link at the bottom of one of your messages if you've used a suppression list, they are shown a screen similar to the one below. They have the choice to remove their address from the list that was used in the communication that sent them the message as well as any other suppression list you have created. Since suppression lists are not global in Dispatch, the recipient can only suppress their address from the communications created by your client when you utilize a suppression list.

The user is also presented with an optional question regarding why they wanted to unsubscribe. The valid options are:

  • I no longer want to receive these emails
  • I never signed up for this mailing list
  • I'm receiving too many emails from The University of Iowa
  • These emails are spam and should be reported
  • Unsubscribed from One-Click mechanism
  • Other:


When a user unsubscribes and adds their address to your suppression list, they are essentially alerting us not to send to them in the future. Dispatch offers the ability to callback to your application to alert you when a person requests adds their address to your suppression list. As Dispatch renders populations for a Communication, it compares the recipients in the population against the list of people who are on your suppression lists. If there is a match, the recipient is marked as excluded from the batch.

Managing lists

Suppression lists can be managed from the Suppression List link available from the Populations page. You can add, edit and delete your suppression lists with several options. You can export the email addresses of those who have elected to removal themselves from your communications. Exports are available as XLSX or CSV. From this page you can view statistics regarding your lists such as the reason why recipients elected to unsubscribe and the daily unsubscribe rate.

You can add the "unsubscribe" link to your communications in one of two ways. Both methods require you to select the suppression list on your communication configuration:

  • Do nothing. The link with the link text you provide will be injected at the end of your message.
  • Use a special marker that signifies where the link should be placed. Simply place #unsubscriptionlink# in your template where you want the full unsubscribe link to appear.

When Dispatch injects the link, it will place the full HTML link including the <a> tag with the link text you provided on the suppression list configuration form. The link will be assigned the CSS class of "unsubscribe-link" so you can customize the display of the link by targeting that class.

List options

There are a few options available for the suppression list.


The name for your suppression list. This value is what is displayed when the recipient visits the unsubscription page.

Unsubscribe link text

You can customize the text that appears in the unsubscribe link.

Communication type

Suppression lists are associated with a specific communication type (Email or Twilio). If a user visits the unsubscribe page, they only see other suppression lists for your client of the same communication type.


If you would like to know when a recipient has unsubscribed from a list so you could adjust populations at their source, you can elect to receive a callback. Callbacks are POST to the URL you specify. Each callback includes a JSON payload like the example below which includes a copy of all the member attributes included in the population that generated the message from which they clicked the unsubscribe link.

Recipients have the option to remove their address from the suppression list. If they happen to remove their address from the suppression list, you will receive another callback but the "action" attribute will be "subscribed" instead of "unsubscribed".

Example request

        "toAddress": "",
        "action": "unsubscribed",
        "actionDate": "Jul 29, 2015 3:37:35 PM",
        "member": {
        "map": {
          "STUDENT_ID": "00099999",
          "FIRST_NAME": "John",
          "LAST_NAME": "Doe",
          "TONAME": "John Doe",
          "TOADDRESS": "",
          "VISIT": "Y",
          "STATE": "IA",
          "COLLEGE": "CLAS"
        "id": "42a63796-34f7-4eee-ad13-d931904e957c"
        "suppressionList": "",
        "reason": "DONT_WANT_TO_RECEIVE",
        "otherReason": ""

If a recipient elects to provide a reason why they unsubscribed, you will receive an additional callback with the reason why the unsubscribed.

Valid reason values are:

  • DONT_WANT_TO_RECEIVE: I no longer want to receive these emails
  • NOT_SIGNEDUP: I never signed up for this mailing list
  • TOO_MANY: I'm receiving too many emails from The University of Iowa
  • SPAM: These emails are spam and should be reported
  • ONECLICK: Unsubscribed from One-Click mechanism
  • OTHER: Other:

Adding and removing suppression records

You can manually add and remove recipients from your suppression lists. This can useful if you receive a request directly from someone who doesn't want to receive your communications and they don't have a message with the unsubscription link to reference.

If you've searched for an email address or phone number and you find a record, you can remove the record by clicking the red delete icon.

You can also import suppression list records in bulk using the Import List function. You can upload txt, csv, xls, or xlsx files. In files that contain multiple columns, you will need to choose the column that contains the email address or phone numbers that need to be imported. Any duplicates discovered during the importation process will be skipped. If callbacks are configured for the suppression list, they will be executed for the records that are sucessfully imported.


You can view two different statistics about your suppression lists. You can view a pie chart of the reason why recipients are unsubscribing from the past 180 days. You can also view the daily number of unsubscribes the list is receiving during the past 60 days.