Mails.ai
mails.ai
What it is
Mails.ai provides email infrastructure and an API for AI agents to send, receive and parse transactional or conversational email. It is available on the web and through an API, with REST, webhooks, an MCP server, and TypeScript and Python SDKs. Inbound replies arrive as structured payloads containing sender, subject, body, headers and attachments, as well as an injection score and sender reputation. All plans scan inbound messages for prompt injection; optional classification can extract intent, entities and urgency for $0.003 per inbound. Listed integrations include Claude Code, Cursor, Cline, Continue, Windsurf, OpenAI Agents SDK, Anthropic SDK, LangGraph, Mastra, Vercel AI SDK and Pydantic AI. The maker describes the product as early, live and self-serve, and says the API refuses cold outreach. Free costs nothing for 3,000 events and one agent. Pro is $20 a month; Scale is $99 a month. Sends stop at a plan's monthly cap; excess inbound replies are stored but not scanned or sent to the webhook. The maker says it lacks SOC 2 today and does not include HIPAA in Phase 1 scope.
Spec sheet
- Product
- Mails.ai provides email infrastructure and a programmatic email API for AI agents to send, receive, and parse email.Read 8 Oct 2026 · mails.ai
- Integrations
- The integrations page lists Claude Code, Cursor, Cline, Continue, Windsurf, OpenAI Agents SDK, Anthropic SDK, LangGraph, Mastra, Vercel AI SDK, and Pydantic AI.Read 8 Oct 2026 · mails.ai
- Compliance
- The maker says it has a GDPR-aligned baseline, does not have SOC 2 today, and does not include HIPAA in Phase 1 scope.Read 8 Oct 2026 · mails.ai
- Support
- The pricing page includes email support on Pro and priority support on Scale.Read 8 Oct 2026 · mails.ai
- API and tools
- The product offers REST, webhooks, an MCP server, and TypeScript and Python SDKs.Read 8 Oct 2026 · mails.ai
- Billing caps
- The pricing page says sends stop at the plan's monthly cap, while inbound replies over the cap are stored but not scanned or sent to the webhook.Read 8 Oct 2026 · mails.ai
- Classification
- Inbound classification can extract intent, entities, and urgency; the features page lists it as opt-in for $0.003 per inbound.Read 8 Oct 2026 · mails.ai
- Dedicated IP
- The features page lists a dedicated IP at $50 per month per IP on Scale+ as an on-request roadmap add-on, and says current beta sending uses the shared pool.Read 8 Oct 2026 · mails.ai
- Inbound replies
- Inbound replies are delivered as structured payloads containing sender, subject, body, headers, and attachments, with injection score and sender reputation included.Read 8 Oct 2026 · mails.ai
- Platform maturity
- The maker describes the product as early and says the API is live and self-serve.Read 8 Oct 2026 · mails.ai
- Security scanning
- The service scans inbound messages for prompt injection on every plan.Read 8 Oct 2026 · mails.ai
- Transport and storage security
- The trust page says public surfaces use TLS 1.3, the primary database is encrypted at the infrastructure layer, and AWS SES message storage uses AWS-managed KMS encryption.Read 8 Oct 2026 · mails.ai
- Use case limits
- Mails.ai is for transactional and conversational email and refuses cold outreach at the API.Read 8 Oct 2026 · mails.ai
Plans and prices
Free Free $0/mo 3,000 events / month · 1 agent · TypeScript + Python SDKs, REST · MCP server · no card Read 8 Oct 2026 · mails.ai
Pro $20 a month $20/mo 5 agents · 50K sends / month · 50K inbound replies / month · custom domain · email support Read 8 Oct 2026 · mails.ai
Scale $99 a month $99/mo Unlimited agents · 250K sends / month · 500K inbound replies / month · per-agent allowlists + budgets · priority support Read 8 Oct 2026 · mails.ai
Strong points and limits
Strong points
- REST, webhooks, MCP server and two SDKs
- All plans scan for prompt injection
- Replies include structured fields and attachments
- Free plan includes 3,000 monthly events
- Listed integrations span agent frameworks and coding tools
Limits
- Cold outreach is refused at the API
- Excess inbound replies are not scanned or webhooked
- No SOC 2 today
- HIPAA is outside Phase 1 scope
Who it suits
Mails.ai suits developers building agents that need transactional or conversational email, structured inbound replies and programmatic controls. It is not for cold outreach through the API.
Verdict
Mails.ai specifies API options, inbound reply data and plan caps, with pricing from free to $99 a month across listed tiers. Buyers should account for the cap behavior and the stated compliance limitations.
Where Specifiction places it
- Cold Email Software#11 of 358.2
