For many small businesses, Microsoft 365 is where work happens. Email, calendars, Teams, SharePoint, OneDrive, and Office apps all connect to the same identity system. That makes Microsoft 365 powerful — and important to secure correctly.
The good news is that small businesses do not need to review every advanced setting at once. Start with the controls that reduce the most common risks: stolen passwords, phishing, exposed files, and overpowered admin accounts.
Require multi-factor authentication
Multi-factor authentication, or MFA, is the first setting to review. Every user should have MFA enabled, especially owners, managers, finance staff, and administrators.
MFA makes stolen passwords less useful because an attacker also needs the second factor. Use an authenticator app or stronger method when possible, and train employees to deny unexpected prompts.
Related service: Email Security
Protect administrator accounts
Admin accounts can change security settings, create users, reset passwords, and access sensitive data. They should be limited to people who truly need them.
Review who has admin rights, remove unnecessary roles, and avoid using admin accounts for daily email. Admin accounts should always have MFA and strong monitoring.
Review mailbox forwarding and inbox rules
Attackers who compromise email accounts often create forwarding rules or inbox rules to hide their activity. They may forward copies of messages externally or move security alerts out of view.
Small businesses should review forwarding settings and suspicious inbox rules regularly. In many cases, automatic external forwarding should be blocked unless there is a clear business need.
Check SharePoint and OneDrive sharing
Cloud file sharing is convenient, but settings can become too open. Review whether users can create anonymous links, share externally, or give broad access to sensitive folders.
Look closely at finance, HR, client, legal, and project folders. Sensitive data should be shared only with people who need it, and external sharing should be intentional.
Turn on security defaults or stronger policies
Microsoft offers security defaults for many tenants. These settings help enforce MFA and block some risky legacy authentication methods. Some businesses may need more customized Conditional Access policies, but security defaults are a useful starting point.
Legacy authentication is especially important because older sign-in methods may bypass modern protections. If your business does not need legacy protocols, they should be disabled.
Monitor sign-ins and alerts
Microsoft 365 provides sign-in logs and security alerts that can reveal suspicious activity: impossible travel, repeated failed logins, unfamiliar locations, or risky users.
Someone needs to review these signals. Alerts only help if they are monitored and acted on.
How Affinity Tech Solutions can help
Affinity Tech Solutions helps Central Florida businesses secure Microsoft 365 with practical settings, MFA, email protection, file-sharing reviews, and ongoing monitoring. If you are not sure whether your tenant is configured safely, we can help you review the highest-risk areas first.
Request a Microsoft 365 Security Review
Frequently Asked Questions
Is Microsoft 365 secure by default?
Microsoft provides strong security features, but many settings still need to be reviewed and configured for your business.
Should every user have MFA?
Yes. MFA should be enabled for every user, not only administrators.
How often should Microsoft 365 settings be reviewed?
At least quarterly for users, admins, forwarding rules, and sharing settings. Review sooner after staff changes or suspicious activity.