So we get e-mails from @microsoft.com and it's only if you dig in the metadata that you see it failed authentication. The only tell in the e-mail is checking the URL, which doesn't tell you much because tons of regular e-mails use tracker redirects too. They even send emails from our own domain or the domain of our payroll company.
I won't type out my rant, but our IT department is a few guys who couldn't figure out what to do when their competitive xbox FIFA 2006 dreams failed, heard IT pays a lot with not much work, and then sat through the certs.