[dmarc-discuss] DMARC thwarted already?

Shal Farley shal at roadrunner.com
Thu Jun 5 10:02:28 PDT 2014

Larry wrote:

> The other was sent to a Yahoo Groups list. As Yahoo Groups has their own 
> workaround this worked.

Notably, Yahoo Groups' workaround is essentially suggestion 3B from the DMARC FAQ item "I operate a mailing list and I want to interoperate with DMARC, what should I do?"

For details see "DMARC-related changes in Yahoo Groups"

The difficulty that has been plaguing Yahoo Groups members (and moderators) ever since that change is that a) some MUAs show only the display name part of the header From field; b) some show only the address part; and c) some show a name looked up from the user's address book. So everyone's experience is different, and rampant confusion has ensued.

The problem in case (a) is exactly what you're talking about - the recipient sees only that the message "came from" the named person. Case (b) causes the opposite problem, the recipient can't tell which list member sent the message, and that's frustrating. Case (c) causes confusion, as the MUAs tend to default to case (a) when the group's address is not in the address book - so a recipient who is a member of multiple groups gets an apparently (to them) arbitrary selection of behaviors.

In other words, it has been a rolling nightmare for group moderators as Yahoo chases workarounds to the workaround. Their first roll-out was suggestion 3A, but that caused immense backlash because so many replies that were intended to be private were instead sent to group posting address. So within two or three days they updated that to 3B. But 3B still leaves holes caused by MUAs that don't implement the Reply-To field.

"Enhancements to email handling"

To mangle a metaphor, DMARC broke it but instead of owning it they've averted their eyes while everyone else injures themselves on the shards of broken pottery strewn about.

-- Shal

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