How does domain linking work in Microsoft 365?
Domain linking in Microsoft 365 means that companies link their own domain to the service for email, Teams and other applications. By verifying the domain, updating DNS records, and configuring services, businesses can ensure users receive professional email and full functionality, while maintaining security and access control.
Steps for domain connection
Connecting a domain requires planning and proper configuration of DNS and services.
Domain verification
Microsoft 365 requires you to confirm that you own the domain via TXT or MX records in DNS.
Update DNS records
For email and other services, MX, CNAME, TXT and SRV records must be configured correctly.
Activate email and Teams
Once the domain is verified, email addresses and Teams accounts with the custom domain can be created.
Security settings
Configure SPF, DKIM and DMARC to protect against spam and email spoofing.
Synchronization with users
Users can be synchronized via Azure AD or local AD to maintain identity and permissions.
Test the configuration
Check that emails are sent and received correctly and that Teams functionality works.
Monitoring and maintenance
Regular checks of DNS and security settings ensure long-term functionality.
Practical tips for domain linking
- Verify the domain: Confirm ownership via DNS records.
- Update DNS correctly: MX, CNAME, TXT and SRV records must match.
- Activate services: Email and Teams are linked to your domain.
- Implement security practices: SPF, DKIM and DMARC protect emails.
- Synchronize users: Maintain identity and permissions.
- Test the functionality: Check email and Teams before full use.
- Monitor continuously: ensure long-term stability and security.
Related questions
Can multiple domains be linked?
Yes, Microsoft 365 allows multiple domains within the same tenant.
What are SPF, DKIM and DMARC?
They are security mechanisms to prevent spam and email spoofing.
Do users need to update anything?
Users may need to configure their email clients with new addresses and new accounts.
How long does domain connection take?
The time depends on DNS updates and verification, but it is often ready within a few hours.
Where are the settings managed?
In Microsoft 365 Admin Center under Domains and in Exchange Admin Center.
