Feeds

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

Purple Palace tweaks security setting, sparks worldwide email bounce blizzard

Build a business case: developing custom apps

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? ®

Endpoint data privacy in the cloud is easier than you think

More from The Register

next story
14 antivirus apps found to have security problems
Vendors just don't care, says researcher, after finding basic boo-boos in security software
Microsoft's Euro cloud darkens: US FEDS can dig into foreign servers
They're not emails, they're business records, says court
'Things' on the Internet-of-things have 25 vulnerabilities apiece
Leaking sprinklers, overheated thermostats and picked locks all online
iWallet: No BONKING PLEASE, we're Apple
BLE-ding iPhones, not NFC bonkers, will drive trend - marketeers
Multipath TCP speeds up the internet so much that security breaks
Black Hat research says proposed protocol will bork network probes, flummox firewalls
Only '3% of web servers in top corps' fully fixed after Heartbleed snafu
Just slapping a patched OpenSSL on a machine ain't going to cut it, we're told
Plug and PREY: Hackers reprogram USB drives to silently infect PCs
BadUSB instructs gadget chips to inject key-presses, redirect net traffic and more
How long is too long to wait for a security fix?
Synology finally patches OpenSSL bugs in Trevor's NAS
prev story

Whitepapers

7 Elements of Radically Simple OS Migration
Avoid the typical headaches of OS migration during your next project by learning about 7 elements of radically simple OS migration.
Implementing global e-invoicing with guaranteed legal certainty
Explaining the role local tax compliance plays in successful supply chain management and e-business and how leading global brands are addressing this.
Consolidation: The Foundation for IT Business Transformation
In this whitepaper learn how effective consolidation of IT and business resources can enable multiple, meaningful business benefits.
Solving today's distributed Big Data backup challenges
Enable IT efficiency and allow a firm to access and reuse corporate information for competitive advantage, ultimately changing business outcomes.
A new approach to endpoint data protection
What is the best way to ensure comprehensive visibility, management, and control of information on both company-owned and employee-owned devices?