Microsoft O365 labels nanog potential fraud?

Grant Taylor gtaylor at
Wed Mar 29 15:25:44 UTC 2017

On 03/29/2017 09:12 AM, William Herrin wrote:
> Both SPF and DKIM are meant to be checked against the domain in the
> envelope sender (SMTP protocol-level return address) which the NANOG list
> sets to nanog-bounces at Checking against the message header "from"
> address is an incorrect implementation which will break essentially all
> mailing lists.

That may be what the original intent was.

Every SPF implementation I've seen has checked the SMTP envelope FROM 
address /and/ the RFC 822 From: header address.

Granted, that does not mean that it's the correct behavior.

Grant. . . .
unix || die

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