Microsoft 365 has become a central part of how many businesses operate. Email, documents, Teams conversations, calendars and shared files may all sit within the same environment, with employees accessing them from the office, home and mobile devices.
When IT Trust takes over the management of an existing Microsoft 365 environment, one of the things we often find is that while the platform is working, the security configuration has not necessarily been fully reviewed or maintained as the business has changed.
Microsoft invests heavily in securing the underlying platform, but that does not mean it is automatically configured appropriately for the business using it. There is a difference between the security built into Microsoft 365 and the way an organisation configures and manages its Microsoft 365 environment.
For a small or medium-sized business, this is not only a technical consideration. It is also a management issue, because the way Microsoft 365 is configured affects access to business data, user accounts, collaboration and day-to-day operations.
Getting Microsoft 365 live is only the start of securing it
When a business moves to Microsoft 365, the immediate priorities are usually practical ones: create the users, migrate email, configure Outlook, provide access to Teams and OneDrive, and get everyone working.
Security can easily be treated as something that is already taken care of because the services are hosted by Microsoft. While Microsoft provides a considerable security foundation, many controls still depend on how the organisation configures its environment, with additional security capabilities depending on its licensing and requirements.
The important point for a business owner is whether someone has taken responsibility for making sure the security configuration is appropriate for the business.
Why Microsoft 365 configuration matters
A Microsoft 365 account can provide access to much more than just email.
Depending on the user’s role and permissions, the same identity may provide access to OneDrive files, SharePoint sites, Teams, calendars, company contacts and other connected applications.
Administrative accounts are more significant still because they can potentially change settings affecting other users or the wider Microsoft 365 environment.
This means that protecting Microsoft 365 identities is an important part of protecting the business itself. Security therefore needs to work in layers. There is no single setting that makes an entire Microsoft 365 environment secure. Several areas need to work together.
Multi-factor authentication is an important starting point
Passwords remain useful, but relying on a password alone creates unnecessary risk. Passwords can be stolen through phishing, reused across services or otherwise compromised without the legitimate user immediately realising.
Multi-factor authentication adds another verification step when someone signs in.
Microsoft describes MFA as one of the fundamental controls for protecting user identities and incorporates it into its Security Defaults. More sophisticated environments may also use Conditional Access policies to control authentication based on circumstances such as the user, application, device or other conditions.
But there is an important distinction between having MFA available and having an appropriate authentication policy in place. A business should understand how users authenticate, whether MFA is being enforced appropriately, and what additional protections apply to privileged administrator accounts.
The objective is to ensure that a stolen password is not enough on its own to provide easy access to business systems.
A common misconception is that enabling MFA means the Microsoft 365 environment is secure. MFA is an important control, but it is only one part of the wider security picture. Administrator privileges, email protection, external sharing, user access, monitoring and ongoing review all contribute to the overall security of the environment.
Administrator access should be tightly controlled
Administrative privileges deserve particular attention because an administrator can make changes that an ordinary user cannot. Microsoft itself recommends treating privileged accounts with additional care and advises separating administrative accounts from accounts used for ordinary productivity tasks.
For an SME, the principle is relatively straightforward: people should only have the access they need to perform their jobs, not unnecessary additional privileges.
It is therefore worth knowing:
- how many administrator accounts exist;
- who uses them;
- what level of access each one has;
- whether they are still required; and
- how those privileged accounts are protected.
This becomes especially important as employees, service providers and IT responsibilities change over time.
Email security requires more than spam filtering
Email remains one of the main ways employees communicate with customers, suppliers and one another. It also remains a common route for phishing, credential theft and malicious files to reach users, which makes email security an important layer of the organisation’s wider security controls.
Microsoft 365 includes anti-spam and anti-malware protection, while additional Microsoft Defender for Office 365 capabilities can provide protections such as Safe Links and Safe Attachments, depending on the organisation’s licensing.
These technologies provide valuable additional layers, but they do not replace sensible configuration or staff awareness.
Attackers increasingly create convincing emails that imitate legitimate business communication. Employees still need to check unexpected requests, verify who actually sent an email, and treat unusual payment, login or document-sharing requests cautiously.
Email security is most effective when technical controls and user behaviour reinforce one another.
Sharing makes collaboration easier, but it also needs oversight
One of Microsoft 365’s strengths is how easily information can be shared. A document can be placed in OneDrive or SharePoint, shared with colleagues, discussed in Teams and accessed from several locations without emailing multiple copies around the business.
That convenience is valuable, but accumulated permissions can create risk.
Over time, an employee may share a document externally for a legitimate project, a contractor might be added to a Team, or a temporary account may be created. We also commonly see employees retain access to folders, sites or information they no longer need after changing roles.
The risk is that access can remain in place after the original business need has disappeared. A former contractor, old guest account or employee with outdated permissions may still be able to access information the business no longer intends them to see.
Security management therefore includes periodically reviewing users, guests, groups, sharing permissions and privileged access rather than assuming that yesterday’s configuration remains appropriate indefinitely.
A secure configuration does not stay static
This is one of the easiest aspects of Microsoft 365 security to overlook, and something we regularly see in existing environments.
A business can start with a well-configured Microsoft 365 environment, but as users, permissions and working practices change, its security can gradually weaken.
This can easily go unnoticed as the environment changes over time:
- Employees join, leave or change roles, altering what access they should have.
- New administrators, contractors or guest users are added.
- Teams, SharePoint sites and shared folders accumulate.
- Employees begin working from different devices or locations.
- New applications and Microsoft 365 functionality are introduced.
- Licensing changes make different security controls available.
Security configuration should not be treated as a once-off setup task. As the business changes, the Microsoft 365 environment changes with it, which means its security controls, access and permissions need to be reviewed and maintained over time.
Questions business owners should be able to answer
Business owners and managers do not need to know how to configure Microsoft 365 themselves. They should, however, be able to establish whether the environment is being managed properly.
Some useful questions to ask the person or provider responsible for administering Microsoft 365 include:
- Is appropriate multi-factor authentication in place for our users?
- How many administrator accounts do we have, and who controls them?
- Are former employees’ accounts and access removed promptly?
- Do we periodically review external users and sharing permissions?
- What email security protections are included in our Microsoft 365 setup?
- Are unusual or suspicious sign-ins and security events monitored?
- When was our Microsoft 365 security configuration last reviewed?
- Who is responsible for responding if an account is compromised?
If nobody can answer these questions clearly, that itself may identify an area worth reviewing.
Microsoft 365 security should be managed, not assumed
Microsoft 365 provides businesses with a capable and continuously developing security platform. But the platform cannot determine every organisation’s users, business processes, acceptable risks or access requirements.
At IT Trust, Microsoft 365 security forms part of the ongoing management of a client’s IT environment rather than being treated as a once-off project. Authentication, administrator access, email protection, sharing permissions and other controls need to be reviewed as users, business requirements and the Microsoft 365 environment itself change.
The practical question for a business is therefore not simply: “Is Microsoft 365 secure?”
It is: “Is our Microsoft 365 environment configured and managed securely?”
For many businesses, a periodic Microsoft 365 security review is a sensible way to answer that question and identify gaps before they become problems.
If you would like to understand how IT Trust approaches Microsoft 365 management and security, visit our Microsoft 365 services page. If you would prefer to discuss your current environment, contact IT Trust and we can help you determine whether a review is appropriate.
