Many Houston businesses assume their Microsoft 365 environment is secure simply because Microsoft continues to add new security features. While that’s partially true, there’s a hidden risk most organizations overlook:
Microsoft only applies many security improvements to new Microsoft 365 tenants.
If your Microsoft 365 tenant was deployed several years ago, inherited from a previous IT provider, or hasn’t undergone a recent security review, older configurations may still be active and exposing your business to unnecessary risk.
At Graphene Technologies, we regularly perform Microsoft 365 security assessments for businesses throughout Houston and often discover legacy settings that could lead to data leaks, compliance issues, or account compromise.
Here are five critical Microsoft 365 security settings every organization should review.
1. Review SharePoint and OneDrive Sharing Settings
One of the most common security risks we find during Microsoft 365 audits involves file sharing permissions.
Older Microsoft 365 tenants often allow users to generate links that grant access to “Anyone with the link.” These links can be forwarded outside the organization without requiring authentication, making sensitive business documents difficult to control.
Why This Matters
A file shared months ago may still be accessible today, even if the original employee has left the company.
Examples include:
- Financial reports
- Client contracts
- HR documentation
- Proposals and pricing information
Recommended Action
Review your SharePoint and OneDrive sharing policies and consider:
- Setting the default sharing option to “Specific People”
- Requiring authentication before files can be accessed
- Applying expiration dates to external sharing links
- Reviewing previously shared documents
Estimated Review Time: 15 minutes
2. Audit External Email Forwarding Rules
Email forwarding remains one of the easiest ways for sensitive information to leave an organization unnoticed.
Microsoft now blocks automatic forwarding to external addresses by default on many newer tenants. However, older mailboxes may still contain forwarding rules created years ago.
Common Risks
Employees may have configured rules that:
- Forward all email to personal Gmail accounts
- Send copies of customer communications externally
- Redirect financial or HR-related information
Recommended Action
Review:
- Microsoft Defender outbound spam policies
- Existing mailbox forwarding configurations
- Historical inbox rules
- Audit logs related to mailbox changes
Businesses subject to compliance requirements should pay particular attention to this setting.
Estimated Review Time: 10–30 minutes
3. Remove Unused Third-Party Application Access
Over time, users often grant access to third-party applications without understanding the permissions being requested.
Many of these applications can access:
- Calendars
- SharePoint files
- OneDrive documents
- User profiles
Microsoft has improved consent controls, but previously approved applications often remain active indefinitely.
Recommended Action
Review all applications connected to your Microsoft 365 environment and remove:
- Unused integrations
- Legacy project tools
- Unknown applications
- Services no longer approved by your organization
Pay special attention to applications with access to mailboxes and company files.
Estimated Review Time: 30–60 minutes
4. Verify Audit Log Retention Policies
Many businesses don’t realize their Microsoft 365 audit logs may disappear long before they are needed.
Audit logs help organizations investigate:
- Suspicious account activity
- Data breaches
- File deletions
- Administrative changes
- Compliance investigations
Why It Matters
Many industries require retaining records for years, not months.
Examples include:
- Healthcare organizations
- Financial services firms
- Legal practices
- Professional services companies
Recommended Action
Review your Microsoft Purview audit retention settings and ensure they align with your:
- Compliance requirements
- Cyber insurance obligations
- Internal security policies
Organizations with Microsoft 365 E5 licensing may be eligible for extended retention capabilities.
Estimated Review Time: 15 minutes
5. Confirm Multi-Factor Authentication (MFA) Is Fully Enforced
If we had to identify the single most important Microsoft 365 security control, it would be Multi-Factor Authentication (MFA).
Unfortunately, older tenants often contain inconsistent MFA configurations.
We frequently discover:
- Users without MFA enabled
- Legacy administrator accounts
- Excluded emergency accounts
- Conditional Access policies with gaps
Recommended Action
Review:
- Microsoft Entra ID Security Defaults
- Conditional Access policies
- Administrative accounts
- Service accounts
- Emergency access accounts
Every user with access to company data should be protected by strong MFA controls.
Estimated Review Time: 1 hour
Recommended Order for Security Improvements
To minimize disruption, we typically recommend addressing these items in the following order:
Low Impact Changes
- Audit Log Retention
- Third-Party Application Review
- External Email Forwarding Review
Moderate Impact Changes
- SharePoint and OneDrive Sharing Controls
Higher Impact Changes
- MFA and Conditional Access Review
Because MFA changes can affect how employees sign in every day, proper planning and testing are important.
Frequently Asked Questions
Are newer Microsoft 365 tenants already secure?
Newer tenants generally receive stronger default protections, but every Microsoft 365 environment should still be reviewed regularly. Historical permissions, sharing links, and application access often remain active regardless of tenant age.
How often should Microsoft 365 security settings be reviewed?
Most organizations should perform a Microsoft 365 security assessment at least annually. Businesses with compliance requirements or cyber insurance obligations may need more frequent reviews.
Does Microsoft 365 include cybersecurity protection by default?
Microsoft provides a strong foundation, but secure configuration, monitoring, user training, and ongoing management remain essential. Default settings alone do not eliminate cyber risk.
What is the biggest Microsoft 365 security risk?
For most organizations, the greatest risks involve weak authentication, excessive sharing permissions, phishing attacks, and forgotten third-party application access.
Need a Microsoft 365 Security Assessment?
Graphene Technologies helps Houston businesses secure, optimize, and manage Microsoft 365 environments through:
- Managed IT Services Houston
- Microsoft 365 Consulting
- Cybersecurity Services
- Microsoft Entra ID Security Reviews
- SharePoint and OneDrive Security Audits
- Compliance Assessments
- Microsoft 365 Migration Services
- IT Support for Small and Mid-Sized Businesses
If you’re unsure when your Microsoft 365 environment was last reviewed, our team can perform a comprehensive security assessment and identify configuration gaps before they become security incidents.