← Cloudflare One / cloudflare-one / email-security / setup / post-delivery-deployment
API deployment
When you choose an API deployment, email messages only reach Email security after they have already reached a user's inbox.
Then, through an integration with your email provider, Email security can auto-move messages based on your organization's policies.
Benefits
When you choose API deployment, you get the following benefits:
- Easy protection for complex email architectures, without requiring any change to mailflow operations.
- Agentless deployment for Microsoft 365.
Limitations
However, API deployment also has the following disadvantages:
- Email security is dependent on Microsoft's Graph API, and outages will increase the message dwell time in the inbox.
- Your email provider may throttle API requests from Email security.
- Email security requires read and write access to mailboxes.
- Requires API support from your email provider (does not typically support on-premise providers).
- Detection rates may be lower if multiple solutions exist.
- Messages cannot be modified or quarantined.