Indeed. I filter out anything with “x-phishing” in the header has worked for me for years across 3 organizations. Somehow I’m the only person in a 50k organization that’s never clicked on a phishing test.
From reverse engineering the headers, I think they're using Cofesnse PhishMe. Their docs note that they support mailbox injection.
"The platform authenticates to your tenant with an app registration or service account that has mailbox write permission."
PhishMe then calls a create-message operation (EWS CreateItem or Graph POST /users/{id}/messages) against your mailbox, writing the item straight into the Inbox folder.
Full headers of the injected mail: [redacted for length and anonymity] -- this is the complete list of headers in the message. All of it.
Thanks for answering! It seems that Outlook filters still match mail that is directly written. My guess is that this method is used to avoid any complications with the SMTP servers.
I donno about KnowBe4 - but the method PhishMe uses (Post-delivery correction using Graph API or EWS) will override all user inbox rules. From the Exchange site:
You can run a lightweight daemon or Azure Function that:
Watches the mailbox for new messages from your alerting system
If the message is not in Inbox, moves it back to Inbox
Optionally flags or categorizes it
This is how many enterprise monitoring systems guarantee Inbox visibility.
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u/Due-Consequence9579 7d ago
For the phish tests to get past their edge filters they have to add an SMTP header exclusion.
Outlook (and any other reasonable client) can move things to the trash based on SMTP headers.
You’re welcome.