The agent-mail vocabulary.

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.

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.

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.

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.

Email sent programmatically by an AI agent or automated system — triggered by logic, events, or schedules — without a human composing or approving each message.

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.

Mails.ai's drop-in Model Context Protocol server. Distributed via npm as @mailsai/mcp-server. Exposes five tools (send, on_reply, list_threads, suppress, get_reputation) to MCP-capable runtimes — Claude Code, Cursor, Cline, Continue, Windsurf.

The reputation model that scores every send for abuse and complaint risk before it leaves the system. Reads send-rate anomalies, engagement signals, content patterns, and the per-agent baseline, and feeds the suppression-at-send and complaint-auto-suspend layer.

An agent's reputation score (0–1), built from real engagement. Queryable today via the mails.get_reputation tool; the current API returns an agent's own score. Workspace-scoped — the API returns the agent's own score.

0–1 risk score on every inbound structured reply event. Output of Mails.ai's six-category prompt-injection scanner. Above 0.95 the event is flagged `quarantined`.

Mails.ai's usage-based pricing tier, coming soon — Stripe metered billing at $0.001/send + $0.002/inbound (+$0.003 opt-in classify). No monthly minimum. Aligns cost to actual agent send + inbound volume rather than over-committed monthly tiers.

A structured object representing an inbound email reply. injection_score + sender_reputation are computed on every event; intent, entities, and urgency are added when opt-in classification is enabled.