DMARC -> CERT?

[scott at doc.net.au (Scott Howard)]

On Mon, Apr 14, 2014 at 11:24 AM, Jim Popovitch <jimpop at gmail.com> wrote:

> DMARC hasn't cut down on yahoo spam so far.   Yahoo's spam problem was
> (is?) centered on account hijacks.
>

I just checked my spam folder for the past month.

Out of about 80 messages "from" Yahoo, I can see about 3 that went via
Yahoo's mail servers. ie, >90% were/would have been blocked using DMARC.

Of course, I'm sure the spammers will simply start changing yahoo.com to
somethingelse.com once they realize - but from Yahoo's perspective, that's
obviously a positive.

Whilst I don't agree with the way that Yahoo has done this (particularly
around communication), I think the end result is only going to be positive.
 At a high level it's no different than when people started rejecting mail
from hosts without PTR records, or when ISPs started blocking outbound port
25 - they both caused things to break, and both caused people to have to
take action to fix the brokenness, but in the long run they were both
hugely positive.

  Scott