Sendmux

Sendmux is an email API for AI agents that combines real mailboxes with multi-provider outbound sending. Agents can send, receive, reply and read cleaned message content through APIs, webhooks, real-time events, MCP, SDKs and a CLI. Teams can route outbound mail through their own Gmail, Outlook or SMTP providers, with quotas, health checks and automatic failover. Pricing is usage-based, with no per-mailbox fees. Start with a free @myagent.mx mailbox.