Ops Log tag
#Hardening
Reviewed Ops Log notes tagged Hardening, written by Michal Jatczak with source links, test context and operational checks.
3 reviewed notes
DMARC at p=none is not protection: what a deliverability check reads from public DNS
A DMARC record at p=none observes spoofing without blocking it. A free deliverability check reads SPF, DKIM, and DMARC from public DNS and tells you exactly which of those three is only watching. Here is how to run it and read it.
July 2026 Exchange Server security updates: confirm the build before removing the interim mitigation
The July 2026 Exchange SUs withdraw Microsoft's advice to keep the CVE-2026-42897 mitigation applied, but installing the update does not remove it. This note gives the per-SKU July build numbers, the PowerShell that reads the real SU level rather than the CU level, and the documented M2 rollback in an order that keeps the exposure window at zero, given that the code fix itself shipped in the June 2026 SU.
Fifteen Microsoft 365 tenant settings that need an explicit decision
Fifteen tenant-wide Microsoft 365 controls, each with the licence tier it actually needs, a read-only Graph, Exchange and SharePoint audit script, the side effects to plan for, and the rollback path. Six pieces of pre-2024 guidance in this area are corrected, five of them attached to numbered rows.