Instantly vs Mails.ai

Instantly combines cold email automation with a built-in B2B lead database for sales outreach. Its outreach tools support automated sequences, unlimited sending accounts, warmup on paid plans, mailbox rotation, reply detection, and multichannel outreach. SuperSearch provides access to a database of 450M+ B2B leads, with filters and email enrichment. Instantly Copilot can find leads, generate campaigns and sequences, summarize analytics, and run recurring tasks. The integration marketplace includes HubSpot, Slack, Zapier, RB2B, BetterContact, and Replit. Growth (Outreach) costs $47 a month, billed monthly, and includes unlimited email accounts and warmup, 1,000 uploaded contacts, and 5,000 emails monthly. Its 14-day trial requires no credit card and allows up to two connected email accounts, 250 uploaded leads, and 1,000 campaign emails. Platforms listed include Android, iOS, web, and API. Instantly names agencies, freelancers, enterprise customers, founders, and sales and marketing teams among its use cases.

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.