Is there quantitative evidence that preventing spoofing of the
"From" address reduces the efficacy of phishing?
According to people I've talked to at large mail providers, apparently
so. DMARC blocks a lot of mail that is clearly phish.
I would have thought that phishers would use any of the bazillion
obvious ways to circumvent DMARC, but they must be as lazy as anyone
else.
R's,
John