Ark

Ark is the revolutionary email API built from the ground up for AI-first developers and multi-tenant software platforms. Forget wrestling with single-sender email services that crumble under the weight of your customers' needs. Ark is the white-label email infrastructure that lets you embed professional, domain-authenticated email sending directly into your CRM, helpdesk, invoicing, or scheduling application. Its native MCP server with 26 tools allows AI agents like Claude, Cursor, and Windsurf to send emails through natural language, eliminating wrapper code and slashing token usage with AI-optimized documentation. Designed for platforms that send on behalf of their users, Ark provides built-in tenant isolation, per-customer domain management, and detailed analytics, so you can stop building email infrastructure and get back to your core product. With sub-second delivery, 99.9% deliverability, automatic email authentication, and a transparent pricing model, Ark empowers developers to ship faster, automate smarter, and scale seamlessly without the enterprise sales calls.

Native AI Agent Integration (MCP Server)

Ark comes with a built-in Model Context Protocol server featuring 26 dedicated tools, allowing AI coding assistants like Claude, Cursor, and Windsurf to send and manage emails directly through natural language prompts. This eliminates the need for boilerplate wrapper code and dramatically accelerates development workflows. The accompanying documentation is specifically optimized for AI readability, reducing token usage by up to 10x and making email functionality a natural extension of your AI-powered development process.

Built-In Multi-Tenant & White-Labeling

Every customer in your platform is fully isolated with their own domains, sending logs, and analytics dashboard. Ark is purpose-built for platforms, making it effortless to manage hundreds or thousands of customer domains from a single, unified interface. This white-label capability ensures your customers' emails come from their own branded domains (e.g., [email protected]), enhancing their professional image and making your platform an integral part of their business operations.

Automated Domain & DNS Management

Onboarding a new customer domain is a breeze. Ark automatically detects the customer's DNS provider (like Cloudflare, GoDaddy, or Route53) and provides them with exact, step-by-step instructions for configuration. For some providers, it can even auto-configure the necessary SPF, DKIM, and DMARC records. This self-service flow eliminates support tickets and Zoom calls explaining TXT records, getting new domains ready to send in minutes.

Real-Time Analytics & Webhooks

Gain complete visibility into your email ecosystem with real-time, per-customer analytics and webhooks. Track delivery rates, opens, clicks, and bounces for each tenant individually. This granular data allows you to instantly debug issues—like a single customer reporting missing emails—without sifting through a monolithic log file. Proactive monitoring and actionable insights are built directly into the dashboard.

Multi-Tenant SaaS Platforms (CRMs, Helpdesks)

Platforms like CRMs and helpdesk software need to send notifications, alerts, and updates from each of their customer's own domains. Ark provides the isolated, white-label email infrastructure required for this, ensuring every client's communications are branded and authenticated properly without the platform developer having to build complex domain management systems from scratch.

Invoicing & Financial Applications

Invoicing tools require high-trust, domain-authenticated emails to ensure payment reminders and receipts reach the inbox and maintain professionalism. Ark enables these applications to send from customer domains like [email protected], directly increasing deliverability and trust for critical financial communications, all managed through a simple API.

AI-Powered Development & Automation Workflows

Development teams using AI agents (Claude Code, Cursor) or automation platforms (n8n, Vercel Serverless, Supabase Edge Functions) can integrate email sending as a native action. With Ark's MCP server and SDKs, sending an email becomes a natural language command or a simple function call within an existing workflow, supercharging productivity for AI-first developers.

Self-Hosted Tool Notification Systems

Tools like Listmonk (newsletters), Coolify (deployment), or Metabase (analytics) that are self-hosted often need a reliable SMTP relay for notifications. Ark's full SMTP relay support allows these tools to send high-deliverability emails without relying on consumer email services, providing enterprise-grade reliability and detailed logs for self-hosted environments.

How is Ark different from Resend or SendGrid?

Ark is fundamentally built for multi-tenant platforms, while services like Resend, SendGrid, and Postmark are designed for a single company to send from its own domains. Ark provides built-in tenant isolation, per-customer domain management, white-labeling, and individual analytics dashboards. Trying to achieve this with other services requires building a complex layer of custom logic on top of their API.

How does the domain onboarding process work?

When a customer adds their domain in your platform, Ark identifies their DNS provider and generates customized, simple instructions for them to add the necessary verification and authentication records (SPF, DKIM). For supported providers like Cloudflare, the configuration can be automatic. This self-service process typically takes customers just a few minutes without requiring your support team's intervention.

Can I use Ark with my existing codebase and infrastructure?

Absolutely. Ark offers full-featured SDKs for Python, Node.js, Ruby, and Go, and integrates seamlessly into any stack. It works perfectly with serverless functions (Vercel, Supabase), automation tools (n8n), and provides a standard SMTP relay for legacy or self-hosted tools. You can plug it into your existing workflows with minimal code changes.

What does "99.9% deliverability" mean?

This means that 99.9% of emails sent through Ark's infrastructure successfully reach the recipient's mail server inbox, not the spam folder. This is achieved through rigorous infrastructure management, automatic configuration of sender authentication protocols (SPF, DKIM, DMARC), and maintained relationships with internet service providers, ensuring your customers' important emails are reliably delivered.

Ark offers simple, predictable pricing designed to scale with your platform. Start with a $29 per month plan that includes 10 domains and 50,000 emails. Scale seamlessly to plans supporting 1,000 domains as your customer base grows. All plans include unlimited team members. For high-volume sending, pay-as-you-go pricing is available at just $0.50 per 1,000 emails. There are no complex tiers or hidden enterprise sales calls. New users can start a free trial with $5 in credits to test the platform.