Microsoft 365 sits at the centre of many businesses: email, files, Teams chats and calendars all live there. That makes it a valuable target. The good news is that a handful of well-chosen settings and habits make a real difference to how well it is protected.
1. Turn on multi-factor authentication for everyone
Multi-factor authentication (MFA) asks for a second check, such as an authenticator app prompt, in addition to a password. It is one of the most effective ways to stop attackers who have obtained a password. Apply it to every user, and especially to administrator accounts.
2. Limit administrator access
Only the people who genuinely need administrator rights should have them, and only at the level required. Use separate admin accounts for administrative work rather than everyday email accounts, and review who holds these roles regularly.
3. Block older, less secure sign-in methods
Legacy authentication protocols do not support MFA and are commonly abused. Microsoft provides Security Defaults for smaller tenancies, and Conditional Access policies for licences that include them. Either approach helps block risky sign-ins.
4. Strengthen email protection
- Review anti-phishing and anti-malware policies
- Set up SPF, DKIM and DMARC records for your domain to reduce spoofing
- Consider additional protection, such as Microsoft Defender for Office 365, where your licence includes it
5. Control how files are shared
SharePoint and OneDrive make collaboration easy, but default sharing settings may allow links that anyone can open. Review external sharing settings and choose the level that suits how your business works with clients and suppliers.
6. Back up your Microsoft 365 data
Microsoft keeps the service running, but protecting your data from accidental deletion, malicious changes or a compromised account is largely your responsibility. A dedicated Microsoft 365 backup gives you an independent way to restore email, files and sites.
7. Help your team spot suspicious activity
Many incidents begin with a convincing email. Short, regular reminders about phishing, unexpected payment requests and suspicious sign-in prompts help staff pause before they click.
8. Review regularly
Microsoft Secure Score offers a useful starting point for identifying improvements. Settings drift over time as staff join and leave, so schedule regular reviews rather than treating security as a one-off task.
Want to know where your own setup stands? Take our free 365 Health Check, see how the Zenvia 365 Secure Baseline puts these practices in place, or book a consultation with Zenvia Technologies.
