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Before diving into the API endpoints, it’s important to understand the key concepts that form the foundation of Mission Inbox’s email infrastructure.

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Relay Servers

A Relay Server is the sending server that handles the actual delivery of your emails. Mission Inbox supports multiple relay server providers to give you flexibility and redundancy in your email delivery.

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Supported Providers

Mission Inbox supports three types of relay server providers:

MissionInbox

Native Mission Inbox infrastructure with optimized deliverability

Mailgun

Integration with Mailgun’s robust email delivery platform

Sendgrid

Leverage SendGrid’s proven email infrastructure

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How Relay Servers Work

Each relay server in your account has:
  • Server ID: Unique identifier for the relay server
  • Provider: The underlying service (MissionInbox, Mailgun, or SendGrid)
  • Configuration: Provider-specific settings and credentials
  • Status: Active/inactive state of the server

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Server Assignment

Mission Inbox automatically assigns relay servers to your account based on your plan and requirements. You can:
  • Use assigned servers: Work with the relay servers already configured for your account
  • Create domains on specific servers: Associate your sending domains with particular relay servers
  • Manage server configurations: Update settings and credentials for your relay servers

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Working with Server IDs

When interacting with the API, you’ll often need to specify a Server ID to:
  • Create domains on specific relay servers
  • Configure sending preferences
  • Retrieve server-specific analytics
  • Manage server settings

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Finding Your Server ID

You can retrieve your available relay servers and their IDs using the API: 
const response = await fetch('https://api-v2.missioninbox.com/api/relay-servers/', {
  method: 'GET',
  headers: {
    'Authorization': 'Api-Key YOUR_API_KEY',
    'Content-Type': 'application/json'
  }
});

const servers = await response.json();
console.log('Available servers:', servers);

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Example Workflow

Here’s a typical workflow for setting up email infrastructure:
1

List Available Servers

Retrieve the relay servers assigned to your account
2

Choose a Server

Select the appropriate relay server based on your needs (provider, location, etc.)
3

Create Domain

Associate your sending domain with the chosen relay server using its Server ID
4

Configure DNS

Set up the required DNS records as provided by Mission Inbox
5

Start Sending

Begin sending emails through your configured domain and relay server

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Best Practices

🎯 Server Selection

Choose relay servers based on your geographic location and target audience for optimal delivery

🔄 Load Distribution

Distribute your sending across multiple relay servers to avoid hitting provider-specific limits

📈 Monitor Performance

Track delivery metrics for each server to identify the best performing configurations

🔧 Regular Maintenance

Keep your server configurations updated and monitor for any provider-specific changes

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Next Steps

Now that you understand the key concepts, you’re ready to:
  • Explore the API Reference for detailed endpoint documentation
  • Learn about domain management and DNS configuration
  • Set up your first relay server and domain combination
Need clarification? These concepts form the foundation of how Mission Inbox manages email delivery. Understanding relay servers and domain associations will help you make the most of the API.