# Use your suppression list

> How the suppression list keeps you from emailing people who complained or opted out, and how to manage it.

Source: https://www.kualo.com/knowledgebase/senders-deliverability/use-your-suppression-list
Updated: 2026-06-10

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A suppression list is the set of addresses that should never receive your emails - people who've complained, globally unsubscribed, or marked you as spam. MailMachine adds some addresses automatically to keep you compliant and protect your reputation, and you can add your own too. This guide explains how it works and how to manage it.

Addresses are added automatically when someone:

- **reports an email as spam** - immediately added to the do-not-send list
- **clicks the global unsubscribe link** and asks not to receive future emails
- **complains** about one or more emails they've received

## Why it matters

Suppression is a compliance and reputation safeguard. By never emailing people who've complained or opted out, you stay on the right side of anti-spam rules like CAN-SPAM and GDPR, and you protect your deliverability - repeatedly mailing people who don't want it is one of the fastest ways to damage your reputation and get blacklisted.

## Add an address directly

1. Click **Audience**, then open the menu.
2. Select **Suppression List**.
3. Click **Add email/domain**. You can add one email or domain at a time.

## Add a contact from your list

1. Open your contact list.
2. Tick the contact you want to suppress.
3. Click **Actions** at the bottom.
4. Choose **Add to suppression list**.

## Removing an address

**Added automatically after a complaint** - these can't be removed yourself. If a contact genuinely wants back in, [open a support ticket](/knowledgebase/getting-started/how-to-create-a-support-ticket-in-mykualo) with the address and proof of their consent (an email from them asking to receive your communications).

**Added manually** - these show as "Manual" and you can remove them:

1. Click **Audience**, then open the menu.
2. Select **Suppression List**.
3. Find the contact and click **Delete**.

:::warning
Before re-subscribing anyone who previously unsubscribed or asked to be removed, you must first obtain fresh, valid proof of consent. Don't add them back without it.
:::

## Troubleshooting

**Can't add an address** - add one email or domain at a time, check the format, remove stray spaces, and make sure you have administrator permissions.

**A suppressed address still gets campaigns** - check for an exact match (and any address variants), allow 24-48 hours to propagate, and confirm the suppression is account-wide.

**Can't remove an address** - system-added entries can't be removed; only manual ones can. For a complaint-based entry, contact support with proof of consent.

**Domain suppression isn't blocking everything** - use the bare domain format (example.com, no @), and note that subdomains may need their own entry.

**Lots of automatic suppressions** - that's a signal to review your content for spam triggers, check your authentication (SPF, DKIM and DMARC), and tighten up list hygiene.

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_Source: Kualo Knowledgebase — https://www.kualo.com/knowledgebase/senders-deliverability/use-your-suppression-list · © Kualo Ltd._