The agent-mail vocabulary.
New to agent email? Start here. Each term is short. Each one means one thing. They’re grouped by category so you can find what you need quickly.
- Distribution
Agentmail
Agentmail is the category of email infrastructure designed for AI agents — dedicated per-agent addresses, structured inbound parsing, prompt-injection scanning, and per-agent reputation, so agents can send and receive email without sharing a human inbox.
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AI email agent
An AI email agent is an autonomous software agent that sends, receives, and acts on email on behalf of a user or system — composing messages, parsing replies, and taking follow-up actions without human intervention.
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AI email content
AI email content is message copy generated by an AI agent for a specific recipient, event, or workflow — then sent, measured, and improved through the email infrastructure around that agent.
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AI email management
AI email management is the practice of using autonomous agents — not humans — to send, receive, classify, route, and reply to email through a programmatic API, with infrastructure-level controls for reputation, injection scanning, and sending policy.
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AI email platform
An AI email platform is infrastructure that gives AI agents dedicated sending and receiving addresses, structured inbound parsing, prompt-injection scanning, and enforced outbound constraints — so an autonomous agent can participate in email conversations safely.
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AI-powered email
Email that is composed, addressed, timed, and sent by an AI agent rather than a human — with replies routed back to the agent as structured events for further action.
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Automatic Mail
Email sent programmatically by an AI agent or automated system — triggered by logic, events, or schedules — without a human composing or approving each message.
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Email
A message sent between addresses over the internet using SMTP — the foundational transport layer that AI agents use to communicate with humans and other systems.
- Distribution
MCP server
Mails.ai’s drop-in Model Context Protocol server. Distributed via npm as
@mailsai/mcp-server. Exposes tools such asmails_send,mails_reply,mails_list_threads,mails_check_suppressionandmails_get_reputationto MCP-capable runtimes — Claude Code, Cursor, Cline, Continue, Windsurf. - Reputation
Classifier
Mails.ai’s check on every send before delivery: fixed rules, then an LLM judge, against a transactional-only policy. Each send’s response carries
classifier_score, and a refused send answers 422 with its reason. - Reputation
Sender reputation
An agent’s reputation score (0–1), built from real engagement and scoped to its workspace. Queryable today through the
mails_get_reputationtool, which returns the agent’s own score. - Security
Injection score
0–1 risk score on every inbound structured reply event. Output of Mails.ai’s six-category prompt-injection scanner. At 0.95 or higher the event is flagged quarantined.
- Pricing
Per-event metered pricing
Usage-based email pricing: every send or received message is billed at a per-event rate, invoiced at month-end, with no monthly minimum. Mails.ai does not offer it; its plans are monthly or yearly, with separate send and inbound allowances.
- Inbound
Structured reply event
A structured object representing an inbound email reply.
injection_score+sender_reputationare computed on every event; intent, entities, and urgency are read from first-contact mail when opt-in classification is enabled on a paid plan.
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