---
title: Introduction to blocklists
slug: campaign/docs/introduction-to-blocklists
docTags: 
createdAt: 2026-07-20T15:44:26.929Z
---

When a recipient is placed on a blocklist, the recipient will receive no more email from you via Optimizely Campaign, even if the recipient registers to receive mailings again. This ensures that your recipient lists have no dissatisfied recipients. And, a clean recipient list with just a few complaints has a positive impact on the [deliverability](docId\:YGM2UPli_WVyiQkluoxnT) of your mailings.

To display the blocklist, open the Optimizely Campaign [menu](docId\:PmNPgvNucBrAG5Rw8f41f) and select **Blocklist** > **Overview**. You can perform the following actions for the blocklist.

## [introduction-to-blocklists.mdx](docId\:bN4TdJLisJkf2KjuWe-wA)Adding recipients to a blocklist

:::hint{type="info"}
**Note**

You cannot add [print](docId\:XHWISDKwuHnaGu9TjmLBm) recipients.
:::

1. Click **Add…**. A blank line is added to the list.
2. In the **Pattern** field, for example, enter the email address or phone number of the recipient you want to block.
3. In the **Reason** field, optionally enter a reason for blocklisting (for example, complaint).
4. Click **Submit**.

## [introduction-to-blocklists.mdx](docId\:bN4TdJLisJkf2KjuWe-wA)Adding recipients to a blocklist automatically

If a recipient marks an unwanted email as spam, Optimizely Campaign is notified by the email service provider, and the recipient is added to the blocklist.

Typical reason for an automatic blocklist entry:

```html
type=automatic;rule=FBL: AOL;mailing=12345678;m2u=987654321
```

:::hint{type="info"}
**Tip**

The **m2u** parameter refers to the mailing-to-user ID, also known as mail ID. The mail ID associates a recipient with a mailing.
:::

## [introduction-to-blocklists.mdx](docId\:bN4TdJLisJkf2KjuWe-wA)Editing blocklist entries

:::hint{type="info"}
**Note**

You cannot edit automatic blocklist entries.
:::

1. To change the reason for blocking, click the entry you want to edit.
2. Click **Edit…**.
3. Edit the content of the **Reason** box.
4. Click **Submit**.

## [introduction-to-blocklists.mdx](docId\:bN4TdJLisJkf2KjuWe-wA)Deleting blocklist entries

:::hint{type="info"}
**Note**

You cannot delete automatic blocklist entries.
:::

1. Click the entry you want to remove from the blocklist.
2. Click **Delete**.
3. Confirm the deletion. The recipient is deleted from the blocklist and can receive your mailings again.

## [introduction-to-blocklists.mdx](docId\:bN4TdJLisJkf2KjuWe-wA)Using wildcards

Instead of entering a complete email address, you can use wildcards in the blocklist entries.

- Use the asterisk (\*) as placeholder for one or more characters. For example, to block email addresses from a specific domain such as *example.com*, specify `*@example.com`.

  :::hint{type="info"}
  **Note**

  Searching the blocklist may result in multiple entries. For example, [axel@example.com](mailto\:axel@example.com) and *\*@example.com* may both be on the blocklist. If [axel@example.com](mailto\:axel@example.com) is removed from the blocklist, Axel would still not receive mails because the *example.com* domain is blocked.
  :::
- Use the question mark (?) as placeholder for a single character. For example, you are not sure about how a name is spelled correctly, such as `Mar?` for *Mark*, *Marc*, or *Mary*.
- You can use placeholders in the domain part of an email address. For example, `abuse@*` blocks email addresses starting with *abuse*. This account name is usually configured by companies and providers as a default email account for customer complaints. If somebody registers for your newsletter with such an email address, it can be both annoying and cause serial problems and damage your internet reputation.