Long running DDOS attack, or overzealous mail administrators?

In exchanging emails with friends and colleagues lately I’m getting more and more NDR’s that bounce back with some message that says “We do not accept spam”.  I knew one such company was small enough that my friend would know the email administrator and sure enough, they have a blanket policy to block any email from a microsoft.com address.

Thankfully none of the customers I deal directly with in my role as a support consultant have this issue, but the issue arose today on a support case where the support contact was a subcontractor working for my customer.  The support engineer had trouble sending updates to this sub-contractor.  We’ve got other ways to reach this person, but it definitely made me stop and give pause.  At my friends place, they are a Mac-centric graphics pre-press outfit and I can here the mail administrator chuckling from across town, but after the third time seeing or hearing about this I wondered if it was all part of some grand scheme to launch a slow moving DOS attack against Microsoft.  Here’s how the conspiracy plays out:

Spoof tons of spam from Microsoft over the course of the years to the point where it is so difficult to separate the wheat from the chaff (so to speak.)  Email administrators the world over get fed up and block all email from the microsoft.com domain.  I certainly hope I am wrong, but I get the feeling that someone out there is going to read this blog who looks a lot like the late George Peppard, he’ll chomp on an unlit cigar and decry, “I love it when a plan comes together.”