Mermail

About Mermail

Mermail is a privacy-first email inbox API built specifically for autonomous AI agents. As agents increasingly need to sign up for services, receive verification codes, and hold ongoing conversations, they need their own email identity rather than borrowing a human's inbox, and Mermail provides exactly that: a real, bi-directional inbox for each agent that can receive email, send replies, search conversations, and handle attachments through a fast, API-backed interface. Unlike transactional email services built only for one-way notifications, Mermail gives agents a genuine mailbox they can act on, so an agent can register for tools, read the confirmation, and reply in-thread just like a person would.

Its defining feature is the privacy architecture. Mermail separates mailbox metadata from full message bodies and attachments, keeping the actual contents in encrypted, user-controlled storage rather than on Mermail's own servers. It routes and mediates access but doesn't retain a decrypted copy of your mailbox; message data is decrypted only when an authorized read happens, and the agent only gets the data it's permitted to see for that workflow. That's a meaningful difference from handing an agent access to your personal Gmail, where every account it touches expands your own attack surface. Mermail is a standalone provider (no Gmail required) that still sends to and receives from any normal email address, and it handles the hard deliverability work, SPF, DKIM, DMARC and IP reputation, so agent mail lands in the inbox. Custom domains are supported on paid plans; a free testnet tier lets developers try it. It's aimed at developers building agentic workflows who need agents to own email safely.