MailChannels is a transactional email API for platforms whose users are the actual senders — multi-tenant SaaS products, workflow and automation tools, web hosts, and AI agent builders.

Most email APIs assume there is one sender: you. That assumption breaks when mail is generated by thousands of downstream customers, tenants, or agents you don't directly control. One compromised account, one runaway agent loop, or one customer importing a bad list can damage the reputation of your entire sending domain — and the usual remedy is to suspend the whole account, taking every legitimate sender down with it.

MailChannels is built for that problem.

Per-tenant sending identity. Every customer, tenant, or agent gets its own sender identity with independent reputation tracking, so a bad sender stays contained instead of spreading across your account.

Per-tenant rate limits and suspension. Throttle, quarantine, or shut down a single sender through the API without interrupting anyone else.

Abuse operations you don't have to build. MailChannels has run outbound abuse detection for web hosting providers for over fifteen years. Compromised account detection, spam and phishing filtering, blocklist avoidance, and spam trap detection are part of the service.

Built for developers. REST API, SDKs for Node.js, Python, and PHP, a Laravel mail transport, a published OpenAPI spec, webhooks for delivery events, and documentation written to be readable by coding agents.

Best fit for: platforms that send on behalf of others — customer notifications, agent-generated messages, white-label sending, hosted applications. Less relevant if you only send your own first-party transactional mail, where simpler and cheaper options exist.

Free up to 3,000 emails per month, then volume-based pricing from $10/month. Outbound Filtering and Inbound Filtering for web hosting providers are separate products with their own pricing.