How to verify and implement the unsubscribe header (Unsubscribe Headers)

To improve and ensure the proper use of bulk email sending, Google and other email providers require the inclusion of an unsubscribe header in all bulk emails to improve subscription management and ensure compliance with email sending best practices.

 

In this guide, we provide the steps to verify and implement the unsubscribe header in your email client, ensuring that your email sending complies with the new requirements and offers your subscribers an easy way to unsubscribe.

 

Who needs to implement this header? 

1. It is mandatory for those sending more than 5000 emails daily.
2. It is recommended for everyone sending any type of bulk emails (Mailman lists, Newsletter mailings, etc.), as it will improve the reputation of all these messages.

 

How to verify if your email has unsubscribe headers configured:

 

To verify if your emails already have unsubscribe headers configured, you can send a test email to services such as mail-tester.com. This tool will analyze your emails and provide you with a detailed report on various aspects of your email, including the presence of unsubscribe headers.

 

When accessing mail-tester.com, it will show you an email address to which you must send a test message from your email address. Once you have sent the message to the provided address, click on “Then check your score”

Note: Example screenshot, SEND THE EMAIL TO THE ACCOUNT THAT APPEARS WHEN ACCESSING mail-tester.com.

 

Next, a score from 0 to 10 will be displayed regarding the reputation of our email account and the different aspects considered insecure or that can be improved.

 

To identify whether the email you sent includes a mailing list unsubscribe header, scroll until you find the section titled “Your message could be improved” and in the last option it will show whether the email has this header or not: 

In this image, it is detected that the message does not contain an unsubscribe header. The report marks this section with a note indicating the need to add it.

 

If your report indicates that the unsubscribe header is missing, it is time to configure it. This is generally done in the advanced options of your email client or through the configuration of your bulk email service.

 

For this guide, we will explain the steps to configure the unsubscribe header from Thunderbird:

 

Steps to add the unsubscribe header in Thunderbird

 

First of all, open your Thunderbird program and access the Settings. In the lower-left section, you can click directly here: 

Next, you need to access Thunderbird advanced settings. To do so, scroll to the bottom of the "General" settings and click on “Configuration Editor”:

A new Thunderbird window will open for advanced preferences. In this search bar, search for the following text:

 

mail.compose.other.header

 

Click on the pencil icon to edit this parameter:

 

 

Then, a text box will open to add new code. The text you must add is the following:

List-Unsubscribe-Post, List-Unsubscribe

 

 

Once the text has been entered, click the blue button to confirm the change.

 

With these steps, you have now enabled the option in Thunderbird to add the unsubscribe button in the header of your messages.

 

When sending a new email, you will be able to enable these two options for the message header:

 

 

By enabling these two options, two additional fields will appear in the Thunderbird compose window so you can add the required configuration for unsubscribing from your mailing list. The text to add is the following, taking into account that you must replace it with your email account information: 

1. List-Unsubscribe-Post: List-Unsubscribe=One-Click
2. List-Unsubscribe: <mailto:youraccountname@yourdomain.com>, <https://www.yourdomain.com/unsubscribe_list_URL.php>

VERY IMPORTANT: You must modify the text of List-Unsubscribe so that it works with your email service data. You need to replace the email account <mailto:youraccountname@yourdomain.com> with the address sending the email and also the URL associated with unsubscribing from your list <https://www.yourdomain.com/unsubscribe_link.php>

 

With these steps, the email will now be sent with the unsubscribe header.

 

If we perform another test send to mail-tester.com, we can verify that it now correctly detects the header and marks it in green:

 

 

You can verify the email header by sending a test message.

 

Example image of an email header with an unsubscribe link:

 

 

 

For more information, you can contact us.

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