Feeds

'Yahoo! Breaks! Every! Mailing! List! In! The! World!' says email guru

Purple Palace tweaks security setting, sparks worldwide email bounce blizzard

Providing a secure and efficient Helpdesk

Email luminary John Levine has accused Yahoo! of sabotaging email lists for everyone, everywhere.

In a post titled “Yahoo! Breaks! Every! Mailing! List! In! The! World! Including! The! IETF's!'”, Levin explains “an emerging e-mail security scheme” called DMARC that “lets a domain owner make assertions about the From: address, in particular that mail with their domain on the From: line will have a DKIM signature with the same domain, or a bounce address in the same domain that will pass SPF [sender policy framework.”

Levine explains that DMARC has weaknesses, notably because “Lists invarably [sic] use their own bounce address in their own domain, so the SPF doesn't match. Lists generally modify messages via subject tags, body footers, attachment stripping, and other useful features that break the DKIM signature. So on even the most legitimate list mail like, say, the IETF's, most of the mail fails the DMARC assertions, not due to the lists doing anything 'wrong'.”

Most of the time that's not a big problem for the world at large. But Levine says “over the weekend Yahoo published a DMARC record with a policy saying to reject all yahoo.com mail that fails DMARC.”

Aside from lots of bounced emails that should go through, here's what Levine says will result from Yahoo!'s change:

“Since Yahoo mail provokes bounces from lots of other mail systems, innocent subscribers at Gmail, Hotmail, etc. not only won't get Yahoo subscribers' messages, but all those bounces are likely to bounce them off the lists.”

In other words lots of email not getting through, lots of automatic unsubscribes and lots of angry users and sysadmins.

Levine offers three suggestions to ameliorate the situation:

  • Suspend posting permission of all yahoo.com addresses, to limit damage
  • Tell Yahoo users to get a new mail account somewhere else, pronto, if they want to continue using mailing lists
  • If you know people at Yahoo, ask if perhaps this wasn't such a good idea

Who wants to be the one to action the third suggestion? ®

New hybrid storage solutions

More from The Register

next story
Google recommends pronounceable passwords
Super Chrome goes into battle with Mr Mxyzptlk
Infosec geniuses hack a Canon PRINTER and install DOOM
Internet of Stuff securo-cockups strike yet again
Reddit wipes clean leaked celeb nudie pics, tells users to zip it
Now we've had all THAT TRAFFIC, we 'deplore' this theft
Apple Pay is a tidy payday for Apple with 0.15% cut, sources say
Cupertino slurps 15 cents from every $100 purchase
YouTube, Amazon and Yahoo! caught in malvertising mess
Cisco says 'Kyle and Stan' attack is spreading through compromised ad networks
TorrentLocker unpicked: Crypto coding shocker defeats extortionists
Lousy XOR opens door into which victims can shove a foot
Greater dev access to iOS 8 will put us AT RISK from HACKERS
Knocking holes in Apple's walled garden could backfire, says securo-chap
prev story

Whitepapers

Providing a secure and efficient Helpdesk
A single remote control platform for user support is be key to providing an efficient helpdesk. Retain full control over the way in which screen and keystroke data is transmitted.
Top 5 reasons to deploy VMware with Tegile
Data demand and the rise of virtualization is challenging IT teams to deliver storage performance, scalability and capacity that can keep up, while maximizing efficiency.
Reg Reader Research: SaaS based Email and Office Productivity Tools
Read this Reg reader report which provides advice and guidance for SMBs towards the use of SaaS based email and Office productivity tools.
Security for virtualized datacentres
Legacy security solutions are inefficient due to the architectural differences between physical and virtual environments.
Secure remote control for conventional and virtual desktops
Balancing user privacy and privileged access, in accordance with compliance frameworks and legislation. Evaluating any potential remote control choice.