nanog mailing list archives
RE: Microsoft O365 labels nanog potential fraud?
From: "Keith Medcalf" <kmedcalf () dessus com>
Date: Wed, 29 Mar 2017 15:05:59 -0600
The purpose of SPF is to REJECT messages before the data phase. This cannot be done if you are checking the RFC-822 From: header since that requires accepting the message and invalidates the entire purpose of SPF. I have never seen an SPF implementation that uses the RFC-822 header From. Doing so would be pointless.
-----Original Message----- From: NANOG [mailto:nanog-bounces () nanog org] On Behalf Of Grant Taylor via NANOG Sent: Wednesday, 29 March, 2017 09:26 To: nanog () nanog org Subject: Re: Microsoft O365 labels nanog potential fraud? 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 NANOGlistsets to nanog-bounces () nanog org. 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
Current thread:
- Re: Microsoft O365 labels nanog potential fraud?, (continued)
- Re: Microsoft O365 labels nanog potential fraud? Grant Taylor via NANOG (Mar 29)
- Re: Microsoft O365 labels nanog potential fraud? Leo Bicknell (Mar 29)
- Re: Microsoft O365 labels nanog potential fraud? Brad Knowles (Mar 29)
- Re: Microsoft O365 labels nanog potential fraud? Florian Weimer (Mar 29)
- Re: Microsoft O365 labels nanog potential fraud? William Herrin (Mar 29)
- Re: Microsoft O365 labels nanog potential fraud? Mel Beckman (Mar 29)
- Re: Microsoft O365 labels nanog potential fraud? Grant Taylor via NANOG (Mar 29)
- Re: Microsoft O365 labels nanog potential fraud? William Herrin (Mar 29)
- Re: Microsoft O365 labels nanog potential fraud? DaKnOb (Mar 29)
- Re: Microsoft O365 labels nanog potential fraud? Carl Byington (Mar 29)
- RE: Microsoft O365 labels nanog potential fraud? Keith Medcalf (Mar 29)
- Re: Microsoft O365 labels nanog potential fraud? Alan Hodgson (Mar 29)
- Re: Microsoft O365 labels nanog potential fraud? William Herrin (Mar 29)
- Re: Microsoft O365 labels nanog potential fraud? Carl Byington (Mar 29)
- Re: Microsoft O365 labels nanog potential fraud? Alan Hodgson (Mar 29)
- Re: Microsoft O365 labels nanog potential fraud? Mark Andrews (Mar 29)
- Re: Microsoft O365 labels nanog potential fraud? Carl Byington (Mar 29)
- Re: Microsoft O365 labels nanog potential fraud? Alan Hodgson (Mar 30)