List-Unsubscribe header doesn't show unsubscribe link in gmail

Question

I manage an email newsletter for a customer. It uses a custom list management utility, but the emails are being delivered through SendGrid.

In order to integrate correctly with our list management unsubscribe. I'm manually creating the "List-Unsubscribe" header, with a mailto address, which goes to an email parser, and unsubscribes the user from the correct publication etc.

The email parsing etc. works fine. However for some reason gmail is not displaying the "Unsubscribe" link in the header, as it does with other newsletters I receive.

Another newsletter I manage for a different customer, uses SendGrid's built-in unsubscribe management, and for these ones gmail does display the link.

What I want to know, is why is my custom "Unsubscribe-Link" ignored by gmail, but SendGrid's works?

SendGrid's "List-Unsubscribe" looks like this ...

List-Unsubscribe: <mailto:[email protected]?subject=http://links.mycustomdomain.com/asm/unsubscribe/*q*user_id=[SHA hash...==]>

My custom "List-Unsubscribe" looks like this ...

List-Unsubscribe: <mailto:u-[custom-encoded-user-id+publication-id]@list-management.mycustomdomain.com>

My email parser reads the incoming "to" address, and interprets the encoded user-id and publication-id, to unsubscribe the person from the correct list.

Can anyone suggest why gmail might not like my link? It's extremely difficult to find detailed information about the requirements for this header.

One obvious difference, is that mine doesn't have a subject, but that's because it doesn't need it. It gets all it needs from the "to" address. Could this actually make a difference though? Does the "to" address need to remain static?

I thought perhaps it just needed time, for gmail to familiarise itself with this newsletter. However it has been running for months, and still no link.

The list is very clean, and all recipients have opted-in. We don't get any spam reports, and very few bounces.

I've gone to a great deal of trouble to ensure that everything works correctly from my end, and it's very frustrating that I cannot find out what I need to do to make this work.

I found a similar question at the gmail forums, and the official response to that question was to "contact a professional about constructing html emails".

Not very helpful for me, as in my case, I'm supposed to be that professional.

Any suggestions would be greatly appreciated.

Mezoff

Might be low sender reputation? https://mcmap.net/q/421194/-gmail-unsubscribe-link-does-not-appear – Hexastyle

Not sure, but you might double-check that the "local part" of the email address is no more than 64 characters long and that the entire email address is no more than 255 characters long. en.wikipedia.org/wiki/Email_address – Aftonag

fwiw, even in iOS Mail, I've seen the header appear sometimes and not other times on our test emails. I'm guessing there's some sort of additional underlying logic influencing whether or not the "unsubscribe" UI is displayed. – Aftonag

Is the issue fixed? – Quaky

I reverted back to using SendGrid to temporarily get around the issue. I may try the custom list management again in the next couple of months. – Mezoff

I also experience this. My List-Unsubscribe header is very non-custom: List-Unsubscribe: <mailto:[email protected]?subject=unsubscribe>, <https://www.example.com/unsubscribe.html> - but the "Unsubscribe" link does not appear in GMail. It is very puzzling.The header is recognised and appoved by mail-tester.com. I think that the comment from @VasiliyZverev links to the correct answer, and that this is duplicate. – Pentode

Does this answer your question? Gmail unsubscribe link does not appear – Pentode

I also have this problem, sort of - We use AutoPilot (now Ortto) for our newsletter. I registered to our newsletter from both my private gmail account, and my work gmail account (with our own domain). I noticed today that the emails I get to my private gmail account have the "Unsubscribe" link in the subject, while in my work inbox I don't see it. It's exactly the same email, and I double-checked - both get same List-Unsubscribe header in the raw email. So yes - looks like there's some additional logic applied, to determine whether to show or not the unsubscribe link. – Waine

Answer 1

Apparently, Google uses some additional heuristics to decide whether the link should be displayed or not. The List-Unsubscribe header could be abused by spammers to validate that their target got the message, and thus, GMail only shows the unsubscribe link if the source of the message has accumulated sufficient trust.

See https://support.google.com/mail/thread/49653586?hl=en&msgid=49801705 for a response posted on Google Support.

There

Answer 2

The format can be a little tricky and it's not well documented but the main thing to check for if you haven't is that if it's correct you should immediately see an unsubscribe link in the dropdown you get when clicking the little toggle next to "to me". It's "unsubscribe from this sender" in my screenshot.

If that's there then the answer and comments about Gmail's secret sender reputation sauce are applicable. You just have to hope they also give you the header button, but if you're not even seeing this in the dropdown then you're doing something wrong with the header value, probably either length or non-url-safe characters.

Keenankeene