It appears to be a sidechannel attack, via targeted delivery to your endpoint. Content not routed through the MX will, naturally, not be inspected, nor match any available content filtering rules.
Meraki equipment is so easy to configure @PhilipDAth taught his cat to do it.
Adam R MS | CISSP, CISM, VCP, MCITP, CCNP, ITILv3, CMNO If this was helpful click the Kudo button below If my reply solved your issue, please mark it as a solution.
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