I have configured SPF, DKIM, and DMARC for a couple of domains that use G Suite as an email/office suite provider. Everything is looking great so far, except for some reason Google is the only provider that is sending us daily aggregate reports, and what's more interesting, the reports Google is sending us include the emails we send to other providers.
To give you an example, the recipients of most of the emails we send are Office 365/Outlook users. Shouldn't Microsoft send us aggregate reports in this case? Well, it turns out no, as we have not received anything from Microsoft and the reports Google is sending us take into account the emails we send to Office 365 users. How is this possible? When we send emails through our G Suite accounts, is it possible for Google to somehow instruct Microsoft's servers to ignore our domain's DMARC email address and instead of that send aggregate reports to Google, which they in turn compile and send to us?
I really can't make sense of this. Any help would be appreciated.
Best Answer
I had the same issue but the explanation is very simple :
There is many people using Office 365/Outlook or other mail provider as a secondary identity and redirect all their mail to their main mailbox (Gmail for example). The consequence is that Google is the real recipient while Microsoft act as a relay.
And according to the RFC 7489(https://www.rfc-editor.org/rfc/rfc7489#section-4.3), only the final recipient send a report, in this case it's Google and not Microsoft even if Microsoft was the original destination. Also, there is only few mail provider which send reports (and i never saw Microsoft sending any).
So, in your case, you have only sent mail to mail providers that act as a relay to a Gmail box (Very common as i have saw in my reports) or which don't send any reports.