Jenny Peters

List-unsubscribe: a reputation improving e-mail header

Written by Jenny Peters Jeffrey Bertoen on

gmail_unsubscribe_NL.gifA number of larger e-mail clients such as Gmail and Hotmail offer an unsubscribe function to their users for commercial e-mailings. This function adds an extra button to the interface of the e-mail program (see image). To activate this function as a sender of commercial e-mail, you need to add a special e-mail header to your mailings. This is called  the list-unsubscribe header. The advantage for the sender is that you'll receive less spam complaints and it will improve the deliverability of your e-mails.

Let's explain this from scratch. A 'header' is the technical information that's added to e-mail messages, such as sender, subject and timestamp. This information is picked up by the receiving mailserver and processed into the delivery of the e-mail. Sender can add headers to e-mails themselves aswell, to give instructions to the receiving system. These headers are not visible to the end recipient (unless he checks out the source code of the e-mail). The DKIM header for example is added to prove the authenticity of the sender.

That brings us back to the list-unsubscribe header. Which adds extra information to an e-mail, instructing the e-mail client to display an unsubscribe button with the e-mail. When a recipient uses that button, a notification is sent back to your system to complete their opt-out from the mailing list. In the header you tell the server where and how you want receive this notification. If you have a (good) CRM package or marketing software it will be able to catch and process these notifications for you automatically.

The main reason for using this header is to manage your sender reputation. If you have a good reputation, your messages are delivered to the inbox of your contacts. If too many of them hit the spam-button, your reputation plunges and all messages will be delivered straight to the junkmail of all recipients. Some recipients will hit the spam button simply because they cannot find or don't bother to find your unsubscribe link. Or they don't want to go through that procedure. This nevertheless affects your reputation badly. The list-unsubscribe header makes the unsubscribe button just as easy to find and use as the spam button. In Windows Live it's not even possible to use the spam button if a list-unsubscribe header has been added to your e-mail!

Another reason to use list-unsubscribe is that recipients can distrust your unsubscribe links in the e-mail. They'll think 'they want to sell so they won't listen' or are afraid clicking will get them a virus. A button integrated into the e-mail client's interface is much more trustworthy for them to use.

And a final reason, spam filters are influenced positively when they see an unsubscribe header in your e-mail. They'll more easily let your e-mail through to the inbox. It's like presenting a guarantee that you're a legitimate e-mail sender. It also makes it easier to monitor your reputation for the e-mail watchdogs (ReturnPath, Lashback, Listbox, a.o.).

Replacing the unsubscribe link
The list-unsubscribe header cannot (yet) replace the regular unsubscribe link you add to commercial e-mails, because not all e-mail clients support the functionality. Microsoft Outlook for example doesn't do anything with this header, whilst Dutch telecom law obligates us to offer everybody an opt-out with every e-mail. List-subscribe could become the new standard for unsubscribing in a few years though. It's easy to setup and readily automated and processed. Moreover the number of e-mail clients integrating this function is growing steadily and includes big names such as Windows Live Beta, Gmail, Yahoo and Yahoo! Groups, and AOL.

List-unsubscribe may be only one of the options available to manage your sender reputation, and not the biggest or most important one, but it's a tool that's easy to use and gets excellent response from recipients. We advice you to add it to all your e-mail templates today!

This article was published in Dutch on