On Thu 07/May/2020 19:35:38 +0200 Michael Peddemors via mailop wrote: > On 2020-05-07 10:19 a.m., Nick via mailop wrote: >> On 2020-05-07 18:07 BST, John Levine via mailop wrote: >>> My users have lots of addresses and my mail system lets them use >>> whatever From: address they want. >> >> Interesting. That seems liberal, and also risky isn't it? What's the >> advantage that makes up for the risk (if you agree there is some)? >> > > Common technique done by compromised accounts, is to use a fake MAIL FROM, > hoping you see less bounce traffic. > > We strongly recommend, 'require_local_sender_domain' and preferably > 'require_local_sender', however there are always ISP's who want to allow some > customers to relay, or are worried that blocking it will impact users, and > cause them to loose money/customers.. > > Not always easy pointing out the risks outweigh the rewards.
The famous DKIM incipit says "to claim /some/ responsibility" [my emphasis], without even trying to specify which. Perhaps, the possibility to be less ambiguous would meet the wants of some kind of filter...? And this thread is really about DKIM, not DMARC. Best Ale -- _______________________________________________ mailop mailing list mailop@mailop.org https://chilli.nosignal.org/cgi-bin/mailman/listinfo/mailop
