The 12 priority settings that raise your Microsoft 365 Secure Score without breaking the user experience. A proven method, used with our Québec SMB and nonprofit clients.
Why Secure Score really matters in 2026
By 2026, the Microsoft Secure Score has become a de facto standard for measuring the cybersecurity posture of a Microsoft 365 organization. Canadian cyber insurers use it as an indicator at renewal, some clients require it in their RFPs, and the CAI may refer to it during a Law 25 audit.
A score of 40/100 - typical of an SMB that has never hardened its tenant - is a red flag. A score of 80+ is a defensible posture. Here's how to get from one to the other in 30 days.
The 12 priority settings (in decreasing order of impact)
Not all settings are equal. Here are the 12 actions that raise your score the fastest, without breaking the user experience:
- MFA required for ALL users (admins AND standard users) through Conditional Access.
- Blocking legacy authentication (POP, IMAP, SMTP basic auth, Exchange Web Services).
- Configuring Microsoft Defender for Office 365: Safe Links, Safe Attachments, anti-phishing policies.
- Disabling Microsoft 365 tenant creation by users (the `AllowedToCreateTenants` setting to false).
- Enabling Microsoft Defender for Endpoint with EDR in block mode on every device.
- Password policy: dropping forced periodic changes (per the NIST/Microsoft recommendation) in favor of long passwords + MFA.
- Purview Sensitivity Labels deployed on files containing personal information.
- A basic DLP policy: blocking credit card numbers and SINs from being sent in outbound email.
- Disabling user consent to unverified third-party OAuth apps.
- Auditing admin accounts: removing accounts unused for 90 days and applying least privilege through Entra ID PIM.
- Enabling quarantine for suspicious emails (instead of delivering them to spam).
- Configuring Microsoft 365 alerts on critical events (admin creation, mailbox rule changes, credential leaks).
A realistic 30-day timeline
To avoid operational breakage, here's the sequencing we use consistently at io4:
Week 1 - Internal communication, fleet audit, break-glass admin exclusions. Turn on legacy auth auditing, disable user tenant creation, harden admin accounts.
Week 2 - Staged MFA rollout (admins, then pilots, then everyone), block legacy auth, Defender for Office enabled.
Week 3 - Defender for Endpoint deployed via Intune, Sensitivity Labels and basic DLP configured.
Week 4 - Audit logs, Microsoft 365 alerts, a final Secure Score pass, documentation.
Pitfalls to avoid
Pitfall #1: enabling MFA en masse without preparing support. Set up a dedicated help desk channel for the 48 hours after the switch.
Pitfall #2: deploying Defender for Endpoint without exclusions for any third-party antivirus already in place - collisions guaranteed.
Pitfall #3: forgetting service accounts. They often use legacy auth for long-standing integrations. Map them before you block anything.
Pitfall #4: aiming for 100/100. Past 85-90, the marginal gains cost a lot in user friction with no real security value. 80-85 is the sweet spot for ROI versus risk.
What it changes in practice
Across 30 organizations io4 worked with in 2024-2025, the average score went from 38 to 76 in 30 to 45 days. The ROI isn't measured by the score alone: it's also -65% in successful phishing incidents, +12% on average in cyber insurance premium reductions at renewal, and a defensible posture in the face of client audits.
For an SMB, it's probably the best week of IT investment you can make in 2026.
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