[opendmarc-users] DMARC and fraudent emails from spf- and dkim-valid domains

[l at avc.su]

Hello.

I've noticed one thing when setting up an OpenDMARC on my domain (for 
example, named example.net):
when I'm sending an email from other domain that has valid SPF and DKIM 
(for instance, example.net.com), and that message has "from: 
example.net.com" in Envelope-from with "from: example.net" in mime 
header, DMARC passes it for example.net.

DNS records for example.net:
_dmarc.example.net = "v=DMARC1; p=none; 
rua=mailto:postmaster at example.net; ruf=mailto:postmaster at example.net; 
fo=1"
_domainkey.example.net = "t=y; o=~"

How can I block this kind of fraud?
Thank you.