"Searching through individual messages for little unsubscribe links is too big a pain —you should be able to unsubscribe with a single click. Now, when you report spam on a legitimate newsletter or mailing list, we'll help you unsubscribe. Clicking "Unsubscribe" will automatically send a request back to the sender so they'll stop emailing you." - Keith Coleman

"For those of you senders who are interested in this feature, the most basic requirements are including a standard "List-Unsubscribe" header in your email with a "mailto" URL and, of course, honoring requests from users wishing to unsubscribe. You'll also need to follow good sending practices, which in a nutshell means not sending unwanted email (see our bulk sending guidelines for more information)." - Keith Coleman

It's funny, but I'm so pragmatic when it comes to marking spam that I'd never think to mark a newsletter as spam unless I'd specifically never requested it. It would be great if Gmail compiled some metrics on whether I read a given newsletter, in the same way that Reader does for feeds. It'd be great if I could go to a page that would remind me that of the 20 newsletters I get, I never (or almost never) read 8 of them, and would I like to unsubscribe? - Kevin Fox

The button I would want is "Unsubscribe, and if they send me another one, mark that as spam." - Seth

Seth: Or the 'Send as last word' button, which will send your email and automatically bounce further emails from the person. - Kevin Fox

The line between spam and non-spam is pretty blurred: Google apparently has a whitelist from trusted newsletter senders for this feature (as they say the dialog won't be displayed for spammers), but where do sites fit in which send dozens never-opted-in-to "x wants to be your friend" or "y updated their address book" etc. messages? - Philipp Lenssen

(And why does the button read "Unsubscribe *and report spam*", when they say they only use whitelisted non-spam senders to trigger this feature anyway, and also ask senders to support the auto-unsubscribe option?) - Philipp Lenssen

I'm really happy to see this is finally out. Philipp, I'm guessing that this feature is based on sender reputation (computed from spam reports), not a manual whitelist. At least that's how it was supposed to be done. I agree with the "needs unsubscribe" button comments -- many people use "report spam" to mean unsubscribe unfortunately. Also, the unsubscribe option should appear in the little arrow menu between "delete" and "report phishing". - Paul Buchheit

I hope other email providers adopt this approach as well -- unsubscribe should be part of the standard email interface. Also, if you aren't seeing this in Gmail, be sure to reload (I had to). - Paul Buchheit

"I'm guessing that this feature is based on sender reputation (computed from spam reports), not a manual whitelist." Paul, but that's exactly what doesn't make sense with the buttons. If you pressing "it's spam" is supposed to influence what is spam and what's not, and this dialog will only show for currently-defined-as-non-spammers senders, then you'd be forced to mark them as spam to unsubscribe (because the button reads "unsubscribe *and* report spam"). - Philipp Lenssen

Ah, Google added an update to their post: "Update (1:50pm): If you want to unsubscribe without reporting the message as spam, click "show details" in the top-right corner of the message, then click "Unsubscribe from this sender."" - Philipp Lenssen