Exchange Online · Mail Flow
Connectors
Manage mail flow connectors that control how email flows between Exchange Online and external systems including on-premises Exchange, partner organizations, and third-party services.
Scope: Mail flow connectors for Office 365
Permissions
- Create inbound and outbound connectors
- Configure partner organization connectors
- Set up hybrid Exchange connectors
- Configure TLS and certificate settings
- Manage smart host routing
- Configure Enhanced Filtering for Connectors
Common use cases
- Hybrid Exchange configuration with on-premises
- Partner organization secure mail flow
- Third-party email security gateway integration
- Conditional mail routing scenarios
- Smart host configuration
Best practices
- Enforce TLS for sensitive communications
- Document connector configurations and purpose
- Test connectors before production use
- Use Enhanced Filtering if mail routes through a service first
- Validate certificates for TLS connectors
Security considerations
- Misconfigured connectors can expose mail flow to interception
- Can bypass security filtering if improperly configured
- Connectors without TLS send email in clear text
- Partner connectors require mutual trust verification