Suppression Groups

The method used to specify an unsubscribe group for an email depends on how you will be sending that email:

• When sending an SMTP message, add the group's ID to the X-SMTPAPI header.
• When sending an email via the Web API v2 , add the group's ID in the x-smtpapi parameter.
• When sending an email via the Web API v3 , define the group's ID in the asm.group_id parameter.

To specify which groups to display on the Manage Preferences page of an email, add the group IDs to the X-SMTPAPI header of an SMTP message, or in the x-smtpapi parameter of a mail.send API call. If you omit the asm_groups_to_display header, your default groups is shown on the Manage Preferences page instead.

You can find your group IDs by looking at the Group ID column in the Unsubscribe Groups UI, or by calling the GET method of the groups resource.

Related Articles:

• You can create Unsubscribe groups via the API V3 > Unsubscribe Groups Endpoint .

• SMTP Service Crash Course
• Getting Started with the SMTP API
• Integrating with SMTP
• Building an SMTP Email