[dmarc-discuss] Strong hint Microsoft is heading to p=reject ?

Terry Zink tzink at exchange.microsoft.com
Wed Apr 6 14:51:41 PDT 2016

This is not related to DMARC.

This is related to our on-prem/hybrid customer base who send email this way:

On-prem --> Office 365 --> Internet

Suppose I want to relay email through the service, and let's suppose I have provisioned the following domains with Office 365:

1. contoso.com
2. woodgrovebank.com

In order to do this, I have to set up a connector from my on-prem to Office 365 that has either (a) the IP address I am connecting from, or (b) a TLS-based certificate. What we see a lot of customers doing is relaying from an IP in one of their connectors and not over TLS (which is permitted) but in the example above, sending email from cohovineyards.com. They - as an organization - may own the domain, but it's not provisioned with us. That's the behavior that we are clamping down on. If you use IP-based connectors, the domain must be provisioned with us. OR, you can use a TLS-cert based connector if the domain is not provisioned with us.

We see many customers putting IPs into their connectors and then relaying from domains that aren't provisioned with us and this causes attribution problems. For example, two different customers can provision the same IP. These attribution problems make outbound spam filtering difficult.

> As I read that, it boils down to Microsoft declaring that
> "old style forwarding" is obsolete

There is some truth to that.

-- Terry

-----Original Message-----
From: dmarc-discuss [mailto:dmarc-discuss-bounces at dmarc.org] On Behalf Of J. Gomez via dmarc-discuss
Sent: Wednesday, April 6, 2016 1:32 PM
To: dmarc-discuss at dmarc.org
Subject: [dmarc-discuss] Strong hint Microsoft is heading to p=reject ?

Hello all.

Please consider this Microsoft blog post, titled "Important notice for Office 365 email customers who have configured connectors":

As I read that, it boils down to Microsoft declaring that "old style forwarding" is obsolete and will not be supported past February 1, 2017, on their Office 365 cloud service.

Could this be a hint that Microsoft is making preparations to roll out "p=reject"? 


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