List-Unsubscribe

What is it?

The List-Unsubscribe header is an optional chunk of text that email publishers and marketers can include in the header portion of the messages they send. Recipients don't see the header itself, they see an Unsubscribe button they can click if they would like to automatically stop future messages.

Right now the header is used to enable an Unsubscribe button in Windows Live Beta (the next version of Hotmail) and for more than a million Cloudmark toolbar users. If history is any guide, we'll see a similar feature in Outlook soon.

A List-Unsubscribe header might look like this:

From: josh@domain.com
Subject: [espc-tech] More info on List-Unsubscribe
Date: August 31, 2006 3:13:02 PM CDT
To: jasmine@domain.com
List-Unsubscribe: <mailto:unsubscribe-espc-tech-12345N@domain.com>, <http://domain.com/member/unsubscribe/?listname=espc-tech@domain.com?id=12345N>

As you can see, it supports both an email based (mailto) and web based (http) unsubscribe mechanism.

The header is defined in RFC 2369 which I wrote with Grant Neufeld back in college.

The List-Unsubscribe header has been widely adopted by software vendors and ISPs, such as Lyris, Majordomo, Microsoft Windows Live, SKYLIST, Yahoo! Groups, and many others.

Senders - why you should include it

Including a List-Unsubscribe header in your emails will reduce complaints, improve deliverability and improve the experience for your subscribers. It's easy to do and doesn't cost anything.

It will reduce complaints because your recipients will be able to easily and reliably unsubscribe if they want to. Frustrated users are likely to hit the "Report Spam" button or complain in some other way about the email that they requested, hurting your sender reputation. In Windows Live Beta, when you enable the Unsubscribe link the Report Spam link is not an option.

Including a List-Unsubscribe header is viewed positively by most ISPs and spam filters, and allows unsubscribe reputation services such as Lashback to more reliably monitor your unsubscribe compliance. User feedeback (the "Report Spam" button) is one of the most significant factors is deliverability at the major ISPs such as AOL, Hotmail, and Yahoo.

There has been a lot of "urban legend" around whether or not you should click on unsubscribe links in email messages you receive. Many ISPs warn against using any unsubscribe messages in the onilne help for their users. The words "click here to unsubscribe" can still set off some spam filters! Using a List-Unsubscribe header provides a standard way for users and software to know how to unsubscribe. Having an Unsubscribe button show up instead of a Report Spam button will make a big difference in how your recipients perceive the messages you send and your organization.

Most importantly, this is drop dead simple to do. Most software packages support it as an option if its not there by default. Most others will allow you to add "custom headers" pretty easily. To start, a generic unsubscribe address such as "unsub-listname@domain.com" is better than nothing - but eventually you should try to provide dynamic email addresses that are more dummy proof such as "unsub-listname-12352B@domain.com" (read more about VERP)

Mail clients - why you should add an unsubscribe button

If you're an ISP that hosts webmail for users or a software developer that creates a mail client (MUA), then you should consider adding an Unsubscribe button to the UI. Including an Unsubscribe button for senders with a good reputation will reduce "false positive" spam complaints, reduce customer service requests, and improve the experience for your customers.

It has critical mass now and will make a difference for your users the day its implemented. By implementing the Unsubscribe button as an alternative to the Report Spam button, no additional screen real estate is needed and it remains a one-click command for the user.

Consumers - why you should click Unsubscribe

Clicking the wrong button could cause you to miss messages you want in the future.

Case study - Microsoft Windows Live Beta

Windows Live Beta has implemented an Unsubscribe button based on the List-Unsubscribe header. It still is in beta so things may change and may want to cut them some slack if some issues are still being sorted out.

In Windows Live Beta, there is an area just above the message headers that show the Subject and who the messages is From where informational messages are displayed. Most messages display a "Report & Delete" link - clicking on this reports the message to Microsoft as spam and adds the sender's From address to the user's personal block list.

If the sender's From address is in the user's address book OR the sender is in the ReturnPath Sender Score Certified program, the List-Unsubscribe header will cause an "Unsubscribe" link to be displayed instead of "Report & Delete".

When "Unsubscribe" is clicked, a message is sent to the address specified in the List-Unsubscribe header (only mailto is supported at this time) and the sender's From address is added to the user's personal block list. I'm worried that this behavior will confuse users when they try to resubscribe later.

List-Unsubscribe in DIRECT

Ken Magill was the first to talk about Microsoft adding an Unsubscribe button to Windows Live Beta.
E-mailers Call For AOL, Yahoo! to Follow Microsoft’s Lead

Honor Roll - Who has implemented it so far?

List-Unsubscribe in ClickZ

Rebecca Lieb's really nailed this issue in ClickZ
E-Mail Marketers Embrace the 'Unsubscribe' Button

Case Study - L-Soft LISTSERV

The Spam-L mailing list is a good example of the List-Unsubscribe (and other RFC 2369 headers) in use for a discussion style mailing list.


From: LISTSERV@PEACH.EASE.LSOFT.COM
Subject: SPAM-L Digest - 26 Aug 2006 to 27 Aug 2006 (#2006-245)
Date: August 27, 2006 10:00:19 PM CDT
To: SPAM-L@PEACH.EASE.LSOFT.COM
Reply-To: SPAM-L@PEACH.EASE.LSOFT.COM
Return-Path: <owner-SPAM-L@PEACH.EASE.LSOFT.COM>
Domainkey-Signature: q=dns; d=EASE.LSOFT.COM; s=BETA1; c=nofws; h=Date:Reply-To:Sender:From:Subject:To:Message-ID:List-Help:List-Unsubscribe:List-Subscribe:List-Owner:List-Archive; b=aetHboV7ctf903C4WKjpd4pfNe9PUOmErrfCwktSe7fdrc4c7H4FpGSSF2YUfYoeUEoHRxznKMia5rHTJL2Pah0t6WTCPirnyhzA3rJUz2ZxJH++Y75owoqrK4nzSM8D;
Sender: Spam Prevention Discussion List <SPAM-L@PEACH.EASE.LSOFT.COM>
Message-Id: <SPAM-L%200608272300194450.0139@PEACH.EASE.LSOFT.COM>
Precedence: list
List-Help: <http://peach.ease.lsoft.com/scripts/wa.exe?LIST=SPAM-L>, <mailto:LISTSERV@PEACH.EASE.LSOFT.COM?body=INFO SPAM-L>
List-Unsubscribe: <mailto:SPAM-L-unsubscribe-request@PEACH.EASE.LSOFT.COM>
List-Subscribe: <mailto:SPAM-L-subscribe-request@PEACH.EASE.LSOFT.COM>
List-Owner: <mailto:SPAM-L-request@PEACH.EASE.LSOFT.COM>
List-Archive: <http://peach.ease.lsoft.com/scripts/wa.exe?LIST=SPAM-L>


This implementation would be better if it utilized VERP to make the List-Unsubscribe URL one-click and foolproof.

List-Unsubscribe and Domain Keys / DKIM

The List-Unsubscribe header works very well with Domain Keys and DKIM. By placing the List-Unsubscribe header within the signed portion of the headers and message, receivers can be sure that the header is legitimate and has not been modified or falsified. As an additional safeguard, receivers might choose to only recognize List-Unsubscribe URLs whose domain name match the authenticated domain.

In this standard example, the List-Unsubscribe header is signed within the DomainKey signature and the URL within matches the domain that has been authenticated.

Domainkey-Signature: q=dns; d=EASE.LSOFT.COM; s=BETA1; c=nofws; h=Date:From:Subject:To:List-Unsubscribe; b=aetHboV7ctf903C4WKjpd4pfNe9PUOmErrfCwktSe7fdrc4c7H4FpGSSF2YUfYoeUEoHRxznKMia5rHTJL2Pah0t6WTCPirnyhzA3rJUz2ZxJH++Y75owoqrK4nzSM8D;
From: LISTSERV@PEACH.EASE.LSOFT.COM
Subject: SPAM-L Digest - 26 Aug 2006 to 27 Aug 2006 (#2006-245)
Date: August 27, 2006 10:00:19 PM CDT
To: SPAM-L@PEACH.EASE.LSOFT.COM
List-Unsubscribe: <mailto:SPAM-L-unsubscribe-request@PEACH.EASE.LSOFT.COM>


This List-Unsubscribe header is suspicious because it is not within the DKIM signature and goes to a different domain than the one that is authenticated.

List-Unsubscribe: <mailto:SPAM-L-unsubscribe-request@PEACH.EASE.ZSOFT.COM>
Domainkey-Signature: q=dns; d=EASE.LSOFT.COM; s=BETA1; c=nofws; h=Date:From:Subject:To:; b=aetHboV7ctf903C4WKjpd4pfNe9PUOmErrfCwktSe7fdrc4c7H4FpGSSF2YUfYoeUEoHRxznKMia5rHTJL2Pah0t6WTCPirnyhzA3rJUz2ZxJH++Y75owoqrK4nzSM8D;
From: LISTSERV@PEACH.EASE.LSOFT.COM
Subject: SPAM-L Digest - 26 Aug 2006 to 27 Aug 2006 (#2006-245)
Date: August 27, 2006 10:00:19 PM CDT
To: SPAM-L@PEACH.EASE.LSOFT.COM


How to get help

If you're having trouble implementing the List-Unsubscribe header or an Unsubscribe button, I'd love to try and help. Send me an email at list-unsub@deliverability.com.

Case study - Lyris ListManager

Here is an example of a default Lyris configuration with the List-Unsubscribe header. Lyris really implemented this well (not surprising since I was working very closely at the time with John Buckman, founder of Lyris).

Not only does Lyris use VERP (notice the numbered codes in the List-Unsubscribe URL) but they also make the List-Unsubscribe header a default on new lists. Administrators can easily turn on the rest of the RFC 2369 headers (List-Info, List-Subscribe, List-Help, etc.) with one click.


From: cavenders@westaradv.com
Date: August 30, 2006 3:22:22 PM CDT
To: Joshua Baer <josh@domain.com>
Subject: Cavenders.com - Labor Day Sale!
Return-Path: <bounce-127080-722348@mailer.sitebrand.com>
List-Unsubscribe: <mailto:leave-127030-722244F@mailer.sitebrand.com>


Interesting juxtaposition - RFC 2368 (mailto)

Funny, I just realized for the first time that RFC 2368, the RFC approved just before the one containing the List-Unsubscribe header, was the spec for the mailto: URL format.

Will Using the List-Unsubscribe Header Harm My Deliverability?

At LashBack, senders are often approaching us asking whether they should use the list-unsubscribe header.  By and large, the biggest concern many senders have is the impact the use of the list-unsubscribe header may have on deliverability. 

While the presence of the word 'unsubscribe' may be perceived as a sign of commercial email, I am not aware of any cases where messages may be filtered for the mere presence of this word, yet alone the list-unsubscribe header.  Several years ago, Spam Assassin did assign points for the list-unsubscribe header, but these tests were moved in version 3.0 (http://spamassassin.apache.org/tests.html). 

If filtering companies and ISPs were to filter mail based on the list-unsubscribe header, they'd be filtering some of the best mail that consumers want, including the following:

Yahoo! Groups
Computer World
Delta Airlines
Bath And Body Works
Bloomingdales
Davids Bridal
Speigel
Time Life
Albertsons
CompUSA
American Express
Creative Labs
JC Whitney
Payless
PC World
Coolsavings
Hotels.com
And MANY more (if you'd like a full list, let me know)

Without spelling out all the benefits of the list-unsubscribe header, I urge senders to ignore any fears of a negative deliverability impact.  Next time, I will spell out how it can actually improve deliverability.

Eric Castelli
CTO
LashBack LLC

Case study - StrongMail Systems

StrongMail has always had the ability to add in custom headers since its inception. This mean of course that any customer can take advantage of the List-Unsubscribe header today and it has already been tested in customer situations with success.

You can specify a specific email address to send un-subscription requests to or even use a un-subscription URL if supported by the receiver. The StrongMail platform offers many different methods for allowing end-users to unsubscribe. As customers take advantage of our extensive reporting system which again includes support and reporting of un-subscriptions internally, they can make this a seamless process when combined with the List-Unsubscribe header.

Here is a screenshot one of the ways you can take advantage of the header:

In StrongMail, the unsubscribe system can also generate a personalized and unique unsubscribe option for each email based on the recipient and campaign. You can apply the uniquie option as well for the List-Unsubscribe header by applying "List-Unsubscribe: ##UNSUBSCRIBETAG##" instead in your header options.

Learn more about Unsubscribe at Lashback

Learn more about Unsubscribe from the Lashback blog

ReturnPath info on List-Unsubscribe

ReturnPath just posted about List-Unsubscribe to their online resource center

Google Gmail recommends List-Unsubscribe

From Google's Bulk Email Sender guidelines:

"Provide a 'List-Unsubscribe' header which points to a web form where the user can unsubscribe easily from future mailings (Note: This is not a substitute method for unsubscribing)."

AOL Unsubscribe button coming soon?

Well, if this posting by Bill Nussey is as prophetic as most of his comments, we may see an Unsubscribe button at AOL in 2007... lets cross our fingers!