List-Unsubscribe Header Makes Unsubscribing Easier and More Trustworthy

Some people don’t trust unsubscribe links, even from legitimate email senders.

Others don’t want to be bothered locating the unsubscribe link in your email.

In both cases, recipients may click the “spam” button in order to unsubscribe – raising your spam complaint rates and possibly reducing deliverability.

Wouldn’t it be nice if ISPs made unsubscribing easier and more trustworthy for users (at the same time reducing your complaint rate)?

One major ISP is already doing so.

List-Unsubscribe Header Allows ISPs to Add an Unsubscribe Button or Link

By adding a “list-unsubscribe” header to your outgoing email marketing campaigns, you enable ISPs to add an unsubscribe link or button into their user interface.

That way, readers who want to unsubscribe, but who don’t want to be bothered with locating the unsubscribe link in your email, can do so without clicking the “Spam” button in their email clients.

How Hotmail Uses the List-Unsubscribe Header

Windows Live Hotmail (for simplicity’s sake, I’m shortening it to “Hotmail”) is the first major ISP to implement support for the List-Unsubscribe header.

Here’s what happens.

When a Hotmail subscriber first gets a message from you (like this welcome message from our Test Drive), since s/he hasn’t added you to the Safe Senders list yet, images and links are disabled.

The top of your email looks like this in Hotmail:

What Hotmail Does When You're Not on the Safe Senders List
(Click the image above to see what the full email looks like.)

When someone clicks the “mark as safe” link, images are turned on and the top of the email changes to include an unsubscribe link:

Hotmail Message with List-Unsubscribe Header

If someone clicks the unsubscribe link, they see an alert box:

Confirm Unsubscribe

When they click “OK” they’re taken to the unsubscribe page:

Unsubscribe Page

What Do I Need To Do To Use The List-Unsubscribe Header In My Emails?

If you’re an AWeber user, nothing at all – we automatically add this header to your campaigns.

We’ll keep you updated on any other major ISPs adopting the list-unsubscribe header (if you haven’t already done so, follow this blog by email or RSS and be the first to know!).


  1. Marc David

    8/22/2008 11:40 am

    Brilliant… this is really helpful because I’m convinced at this point that many people are just lazy and use the:

    * spam
    * message isn’t safe

    As a way to get rid of it. Which is very unfair to the person who’s following all the rules.

    Every little bit helps.

  2. Colin Greig

    8/22/2008 1:48 pm

    very neat!

  3. Mike Herberts

    8/22/2008 2:38 pm

    I read a lot of IM stuff and find it amusing that certain marketers are scared to make the unsubscribe option easy to access.

    They just don’t get that subscribers couldn’t care less about calling your mail spam and these marketers actually do their best to make it more difficult for someone to unsubscribe.

    It is usually this type of marketer who brags about the size of his/her list without understanding that a huge unresponsive list is worth a lot less than a smaller responsive, ‘eager to get your stuff’ list.

    I thank you once more aweber for being our eyes and ears and keeping us up to date with changes.

  4. John W. Furst

    8/22/2008 7:35 pm

    Hi Justin!

    Looks like a good thing. I already have spotted the header.
    It’s not only the ISPs, the software developers can use this
    field too and add functionality into email clients.

    A good thing for list owners and for users.

  5. Soeren

    8/25/2008 12:24 am

    And how to put that unsubscribe link inside the message, at the top of the message?

    This would be great!


  6. Justin Premick

    8/25/2008 10:02 am


    AWeber users can use the {!remove_web} variable to insert the unsubscribe link anywhere within their messages.

  7. Justin Hitt

    8/25/2008 3:12 pm

    Thank you! A very innovative feature. How many mail readers and ISP’s have adopted it? Do you have a guide for implementation?

    A couple times a year I actually ask people to unsubscribe if they aren’t getting anything out of my messages. Making it easy to get off my list is very important, if they don’t want the e-mail, no sense sending to them.

  8. Marc Kline

    8/25/2008 5:31 pm


    So far, this is implemented solely for Hotmail, but we will keep our eyes open for other ISPs that open the door for this type of useful feature.

    The beauty is that you don’t need to do anything to implement it – it’s taken care of on our end – so no guide is needed.

  9. Gobala Krishnan

    8/26/2008 2:51 am

    If people don’t actually click on "Mark As Safe" after getting like 2-5 emails from you, does Hotmail automatically route all your emails to spam? That’s my concern really..

  10. Soeren

    8/26/2008 6:24 am

    Thank you, Justin!

  11. Justin Premick

    8/26/2008 9:15 am


    I haven’t seen evidence of that occurring now.

    However, I think that sort of thing IS likely to affect deliverability moving forward.

    An interesting discussion took place earlier this month on what criteria ISPs might use to process and filter incoming email in the future.

    Worth reading/thinking about.

  12. Buddy Logan

    8/26/2008 10:52 am

    So – Hotmail says "We may also share this e-mail with companies who help us fight junk"

    And this is a good thing???

    A user hits the spam button and the e-mail is listed as spam … or, they unsubscribe and HotMail intercedes in my unsubscribe process and records my mailing list as junk mail and shares it with other ISP’s.

    And aweber gives me no choice in this matter.

    My unsubscribe links are already at the top of the page, and they take the user to a nice, friendly "Sorry to see you go, hope you come back again" page with a comment area. Someone please tell me why it is to my benefit to subvert this process and have my e-mails listed as junk!

  13. George Bilbrey

    8/27/2008 7:18 am

    Currently, Hotmail’s implementation of the unsubscribe header doesn’t work for all mail sent to Hotmail. Currently, it just works senders that are considered "safe": (1) because they have been marked as safe by the user or (2) the sender is on the Sender Score Certified program.

  14. Justin Premick

    8/27/2008 7:58 am

    Hi George,

    Thanks for stopping by & clarifying.

    I did note that this happens after the recipient clicks "mark as safe" – but maybe I should draw it out more.

  15. Eliza J.

    8/27/2008 9:52 am

    Thanks a lot Justin.

    Very useful and it

  16. Buddy Logan

    8/27/2008 11:45 am

    Justin –

    That doesn’t clarify the issue in my mind.
    If HotMail says they are going to declare my e-mail as "junk" and share my e-mail with other companies to help them fight "junk", then I have to assume that is what they are going to do. This may very well take the choice out of the hands of the recipient at those third-party mailboxes.

  17. Justin Premick

    8/27/2008 12:29 pm


    I can understand your concerns, but to be honest I don’t agree with your assessment.

    Here’s my thinking:

    The note from Hotmail says "we may also share this e-mail with companies who help us fight junk."

    Nowhere in Hotmail’s statement do they say "thanks for reporting this as junk" or anything to that effect. They’re not saying the message is junk.

    In fact, when you look at the unsubscribe area that Hotmail inserts into the email, it says "You’re subscribed to this mailing list."

    Seems to me by telling the user that s/he is subscribed, and by providing an unsubscribe option, Hotmail is consciously differentiating between that message and spam/junk.

    And THAT’S the information I think they may be sharing with 3rd party filtering services — which emails people are clicking "unsubscribe" from, and which ones they’re clicking the "Junk" button in Hotmail for.

    Which I think we can agree is a good thing for legitimate senders (the ones whose readers use the "unsubscribe" link, rather than the "Junk" button) .

  18. John W. Furst

    8/27/2008 1:01 pm

    @Buddy + @Justin

    When I read this Blog post I thought, "What a dumb idea!", at first. But I scanned the post rather then read it comprehensively. I was mistakenly thinking clicking the Spam button, will unsubscribe you instead of reporting the email as spam.

    I re-read the post and it became clear to me, this is a good thing. Hotmail reminds the users that they have subscribed, making them think twice before hitting SPAM. (as Justin just pointed out again) I even would go as far as asking people an extra question, when they hit SPAM on a message that carries the SUBSCRIBED information.

    "Wait a minute!
    Is this really SPAM? You originally have signed up with this email list {on date} {at url}. {Button yes spam}{Button no I just unsubscribe}"

    My humble 19 cents (inflation!)

  19. Buddy Logan

    8/27/2008 2:30 pm

    John – That would be great if they received that message when they hit the "spam" button, but I don’t see anything in this discussion that states that is what happens, except in your post, and, even if that were the case, they can still leave out the line that states they will be sharing this information with other parties which may or may not do with it what you might hope they would do.

    Having gone through the experience of one company blacklisting my mail server because it was in the middle of a block of IPs owned by my hosting company, of which only one IP in that block was found to be spamming, and having to contact each blacklisting web site (used by anti-spam software) that company notified, blacklisting my company as a spammer, and losing a good potential client in the process, I am very leery of any potentially negative information one party releases to another.

    Justin – Please don’t think I am trying to give you a bad time, but your last post has a lot of what you think or assume. I would think that aWeber would need to KNOW before implementing this header info.

    I think the basic idea of information in the header is good. It is just the apparent planned usage on the part of HotMail and the potential abuse that would just be adding another problem to the already time consuming work of maintaining list integrity while not losing customers who want to be there.

    My humble 20 cents (inflation knows no barriers)

  20. Richard Hill

    8/27/2008 5:23 pm

    I agree with John’s comment. You should be a bit more gentle in the wording since those who are already nervous do not need to read scary rules. And though I know very well what the law says about up to 10 days for the sender to unsubscribe the recipient, it is patently ridiculous to bring it up when the unsubscribe will be near instantaneous.

    No mention of sharing will ever be acceptable to me. I don’t share my list and I see no reason for anyone unsubscribing to have their address shared.

    I would also suggest that Hotmail not be the primary test target. They are going to be after strict wording, as in the example. To me, it reads "Run away, run away!" as the Monty Python mob would say. 🙂

  21. John W. Furst

    8/28/2008 10:18 am

    The implemention of the extra message, "Wait a second…", that I was talking about as an example lies in the realm of email client software developers and big webmail providers like hotmail, google mail. AWeber could not really do anything about it other than make it possible by having implemented those extra SMTP Header. (Are those headers based on a particular RFC(s) or just a free implementation by AWeber? I am curious.)

    My 22 cents

  22. Justin Premick

    8/28/2008 10:54 am


    No offense taken 🙂

    I didn’t mean to imply that we didn’t examine the List-Unsubscribe process before implementing it. I just wanted to present another way to look at that statement.

    Keep in mind: just because Hotmail doesn’t put a similar message up when someone clicks the "Junk" button, doesn’t mean that they don’t share *that* information with other parties, too.

    Fighting junk is something we all do – it’s not about ISPs working against senders, it’s about ISPs and legitimate senders collaborating (through tools like this List-Unsubscribe header) to distinguish legitimate mail from spam.

    I think John’s comment just above this one hits the 22-penny nail on the head. The List-Unsubscribe header was developed to reduce false spam complaints and help legitimate senders get more email delivered (remember, ISPs have a responsibility to not block legitimate mail – otherwise their users get mad at them). How an individual ISP implements it is beyond our control as an email sender.

    John (and everyone else),

    You can learn more about the header here:

    That page includes a link to the RFC as well as a brief explanation of the case for using the header.

  23. Buddy Logan

    8/28/2008 12:23 pm

    My comments are rather pointless, actually, as it looks like this thing has already taken off.

    Good stuff:
    "In Windows Live Beta, when you enable the Unsubscribe link the Report Spam link is not an option." ( Cool!

    "Using a List-Unsubscribe header provides a standard way for users and software to know how to unsubscribe." (

    Not so good:
    When "Unsubscribe" is clicked… the sender’s From address is added to the user’s personal block list.

    Senders with multiple lists should be cautioned that they will need to have independent return addresses, or the recipient may inadvertently remove their name from ALL of the sender’s lists. This should not be a problem with AWeber, however, it can create some real problems if the user tries to resubscribe to the particular list.

    Other mailing list services or software may suffer, as they keep track of subscribers by address only. Once the subscriber gets to the unsubscribe page, they then can pick WHICH lists they want to unsubscribe from. Hopefully, these types of problems are being worked out.

    As Rebecca Lieb from The ClickZ Network ( ),
    "Another wrinkle: when recipients hit ‘unsubscribe,’ the sender’s address is automatically added to a block list. They’ll never get mail from that sender again, not even an unsubscribe confirmation. This raises obvious hurdles if someone wants to re-subscribe (some people unsubscribe when on vacation, for example). Moreover, the recipient won’t necessarily know the address is blocked for their account."

    So, it will be up to the sender to make sure, on their unsubscribe page, to inform the subscriber of the process and what it entails.

    I still don’t like Microsoft’s line "We may also share this e-mail with companies who help us fight junk", but I need to complain to Redmond about that, and I will.

  24. Daniel McGonagle

    9/1/2008 6:39 pm

    Hi good post here.

    Have you ever done a study of what the worst free email addresses are for deliverability?

    For instance it seems like Yahoo and AOL are the worst and Gmail is much better, while office emails are subject to scrutiny of their IT people if people are subscribing from work.

    Also, it would be awesome if you could make some of the Whitelist HTML pages that we can customize.. you know, the ones that say;

    "Please whitelist the listname for AOL users, do this… Yahoo users do this" etc…

  25. Greg

    9/9/2008 6:27 am

    Is it necessary to segment your list according to the domain name, so that only Hotmail users have the code allowing for the Hotmail integrated unsubscribe, or does the code simply disappear in other mail clients? I’d love to get feedback on this as this is not something I would implement if it required another segmentation on top of my existing ones… Thanks!

  26. Ellen

    8/19/2009 4:54 pm

    I wish HotMail gave ME a button to unsubscribe people who setup "vacation reply" messages to spam me. I just got 5 when I sent out a newsletter. Typical one says something like:

    Hi friend:

    Introduce you a good website: xxxxxxxxxxxxx

    It is a large wholesaler who trade mainly in all kinds of electronical products for promotion. To my surprise, their products are very low price and high quality.

  27. What to Do About Low Email Delivery Rates

    6/13/2011 9:08 am

    […] Use an Unsubscribe Header […]