Glossary
The vocabulary of email for AI agents - each term defined in plain language, with links to the guides that go deeper.
Terms
Agent Mailbox
An agent mailbox is a real, persistent email inbox that an AI agent owns and operates - it can send messages, receive and read…
Read definitionDKIM, SPF, and DMARC
DKIM, SPF, and DMARC are the three DNS-based standards that authenticate email and protect a domain from being spoofed. SPF…
Read definitionEmail for AI Agents
Email for AI agents is email infrastructure designed for autonomous software to use directly - a real mailbox an agent owns, that…
Read definitionEU data residency (for email)
EU data residency for email means the mailboxes and the processing behind them are stored and run on infrastructure physically…
Read definitionInbound email API
An inbound email API is an interface for receiving and reading email that arrives at an address, returning each message as…
Read definitionMCP Email Server
An MCP email server is a server that exposes a mailbox's actions - send, read inbound, list messages - as tools an AI agent can…
Read definitionProgrammatic mailbox
A programmatic mailbox is a real, individually addressed email inbox that software creates, owns, and operates over an API -…
Read definitionPrompt injection (via email)
Prompt injection via email is an attack in which adversarial instructions are hidden inside an email's content - its body,…
Read definitionScoped API key
A scoped API key is a credential that grants only a specific, limited set of permissions - so the holder can do exactly what it…
Read definitionTwo-way email API
A two-way email API lets software both send and receive mail through one persistent mailbox, then read the replies back as…
Read definition
Start with the fundamentals
New to email for agents? The 2026 guide to email for AI agents ties these terms together end to end.
Give your agent a real mailbox
Two-way email over REST and a native MCP server - EU-resident by default.
EU data residencyPer-customer encryptionNative MCP