Home Forums FineTunedMac Community Lounge Yahoo (and others) Break Mailing Lists

Someone care to comment on the practical implications of this article?

Does it affect responses and/or posts via email? Maybe I don't do what the article says will no longer be possible, so I'd like to know what I haven't missed.

First off, I have to say that I'm not impressed by the clarity of that Slashdot article. In fact, I think it's an unadulterated mess, and that includes the difference between Yahoo's handling of forwarded vs. direct mailing list messages, and the (missing) definition of a Yahoo 'user' (presumably anyone with a Yahoo login when logged in to Yahoo).

As to your question, the way I see it through the Slashdot fog is that you are not affected when you're not a Yahoo or Yahoo partner subscriber. It seems Yahoo shot itself (read: its users) in the foot with its DMARC implementation.

OK, nice to know I'm not the only one.

So now what is your understanding if someone is a Yahoo user? What have they lost?

Yahoo users have lost the ability to use their Yahoo email address on web sites (read: social media etc.), as well as the ability to use a desktop email client with their Yahoo email address; only Yahoo web mail will work. This is because Yahoo now blocks mail containing a Yahoo 'from' address when mail (SMTP) servers other than Yahoo's are used. A similar change also happens when you post to mailing lists which forward the message to other list subscribers, and this effectively bars Yahoo users from using them.

Non Yahoo users also lose out, because once blocked they won't see those Yahoo originating messages either.

If you're interested in (some of) the nitty gritty, here are two articles describing things in more detail:

- Yahoo email anti-spoofing policy breaks mailing lists
- Up in arms about Yahoo's DMARC Policy? You're not alone

Makes you wonder if Yahoo thought this one through completely. Or if there was a disconnect between the tech side and the development end.