---
"@context": https://schema.org
"@type": TechArticle
"@id": https://www.twilio.com/docs/sendgrid/for-developers/sending-email/suppressions#article
headline: Suppression Groups
description: Suppression groups, also called unsubscribe groups, let recipients unsubscribe from some types of your Twilio SendGrid email instead of all of it.
url: https://www.twilio.com/docs/sendgrid/for-developers/sending-email/suppressions
inLanguage: en
dateModified: 2026-07-23T16:57:51.000Z
author:
  "@type": Organization
  name: Twilio Developer Education Team
publisher:
  "@type": Organization
  name: Twilio
---

# Suppression Groups

Suppression groups, also called unsubscribe groups, are categories of email that a recipient can choose to unsubscribe from, so a recipient can opt out of some types of email without unsubscribing from all of them. You assign an unsubscribe group when you send an email, and you choose which groups appear on a recipient's Manage Preferences page.

## Defining an Unsubscribe Group When Sending

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](/docs/sendgrid/v2-api/mail), add the group's ID in the `x-smtpapi` parameter.
* When sending an email via the [Web API v3](https://sendgrid.api-docs.io/v3.0/mail-send/v3-mail-send), define the group's ID in the `asm.group_id` parameter.

> \[!CAUTION]
>
> You may only specify one group per send, and you should wait one minute after creating the group before sending with it.

> \[!CAUTION]
>
> When passing `asm_group_id` please make sure to only use integers as shown in our examples. Any other type could result in unintended behavior.

```json
{
  "asm_group_id": 1
}
```

## Defining Unsubscribe Groups to display on the Manage Preferences page

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](https://sendgrid.api-docs.io/v3.0/mail-send/v3-mail-send).
If you omit the `asm_groups_to_display` header, your default groups is shown on the Manage Preferences page instead.

> \[!CAUTION]
>
> You can specify up to 25 groups to display.

```json
{
  "asm_groups_to_display": [1, 2, 3]
}
```

## Groups

You can find your group IDs by looking at the Group ID column in the Unsubscribe Groups UI, or by calling the [`GET` method](https://sendgrid.api-docs.io/v3.0/suppressions-unsubscribe-groups/retrieve-all-suppression-groups-associated-with-the-user) of the groups resource.

Related Articles:

* You can create Unsubscribe groups via the [API V3 > Unsubscribe Groups Endpoint](https://sendgrid.api-docs.io/v3.0/suppressions-unsubscribe-groups/create-a-new-suppression-group).

## Additional Resources

* [SMTP Service Crash Course](https://sendgrid.com/blog/smtp-service-crash-course/)
* [Getting Started with the SMTP API](/docs/sendgrid/for-developers/sending-email/getting-started-smtp/)
* [Integrating with SMTP](/docs/sendgrid/for-developers/sending-email/integrating-with-the-smtp-api/)
* [Building an SMTP Email](/docs/sendgrid/for-developers/sending-email/building-an-x-smtpapi-header)