Mailbase

Mailbase is a cold email platform built on the French company register. You describe the kind of customer you sell to, and it pulls every matching company from the register, finds and verifies an email address on each company's own website, writes one email per person from a real fact about them, and sends a few a day once you approve. Replies land in an inbox sorted by intent. Behind that prospecting agent sits a full email workspace: MJML templates, campaigns, A/B tests, triggered journeys, audiences with hosted forms, analytics, a REST API for transactional mail and an MCP server. The footer says "Made in France," and the site is published in English and French. The features page is direct about the focus: "We didn't build a marketing suite. We built the pieces a person selling to French businesses actually needs."

What a sender actually gets

Prospecting from the register. Discovery runs on SIRENE, the official French register, filtered by activity, place, size and age and deduplicated on each company's SIREN number. The engine then finds the company's website, reads the legal notice for the published email and the owner's name, and checks the address against the mail server (mailbox and catch-all) before anyone writes. The homepage shows one measured run, electricians in Saône-et-Loire with 1 to 9 staff: 145 companies found, 15 websites confirmed, 13 emails verified and 5 wrong sites rejected, all "on a public register, no paid data." Each draft is written from one fact on the prospect's site, in your voice, and kept under 120 words. The pricing FAQ is clear on geography: discovery "covers companies registered in France, whatever language you write in," while campaigns, the inbox, the assistant and the API work for any audience anywhere.

Guardrails for cold sending. You approve the first batch of drafts yourself; auto-sending opens up only after that, and you can switch back any time. Sending runs inside a daily cap and hours you set, with one or two spaced follow-ups, and a reply or a bounce stops the sequence for that company. Sending pauses automatically on bounce and complaint thresholds. Clients, competitors and past contacts can be blocked by company, domain or address, every draft is screened for patterns that get domains blocked, and every send carries List-Unsubscribe headers and a shared suppression list. On legality, the homepage says B2B prospecting by email is allowed in France with a professional address, a clear sender and a working opt-out, and that Mailbase adds all three on every send.

Reply inbox. Replies are sorted on arrival into groups such as hot, warm, objection and out of office, with a reply drafted where one is needed and tags you control. Responses thread back to the contact who received the send.

Campaigns, templates and tests. Templates use MJML, with a structured section editor or raw MJML source, a brand kit, spam-content and link checks, version history and a live preview that renders the same MJML recipients receive. Campaigns can be scheduled with a timezone, and send jobs retry per recipient. A/B tests take two to four variants, a pilot share, the metric you care about and a confidence threshold; Mailbase picks the winner, by reply rate in the example, and rolls it out in one click.

Journeys, audiences and forms. An import, a tag, a reply, an engagement event or a date can start a journey with send-email and webhook steps, deduplication and exit rules, and a run log per contact. Audiences come from CSV import with saved mappings and duplicate detection, rule-based dynamic segments with live counts, and hosted double opt-in forms you can embed. Contact profiles hold every send, event, reply and note.

Analytics. Per-campaign rollups cover delivery, opens, clicks and replies with machine opens and clicks removed, plus clustered bounce and complaint reasons and UTM source tracking on every link.

AI assistant. Ask in plain words and the assistant proposes: a reply draft lands in the reply box, campaign copy lands in the composer, and nothing sends until you press send. The pricing FAQ says you can connect your own provider key (OpenAI, DeepSeek, OpenRouter, MiniMax, Groq, Mistral or any OpenAI-compatible endpoint) and run the assistant unmetered at your own cost.

Sending, API and integrations. You either verify your own domain and send through Mailbase, which shows the exact DKIM and SPF records to set, or connect your own useSend instance. The docs cover SPF, DKIM and DMARC status per sender domain, unsubscribe compliance, and cron setup for self-managed jobs. The REST API sends transactional email and manages contacts, audiences, templates and campaigns, with an OpenAPI contract, scoped tokens, idempotency keys and signed webhooks; every endpoint is scoped to one workspace. A remote MCP server connects Claude Code, Cursor, Codex or other MCP clients with OAuth-scoped access, and REST Hooks connect Zapier, Make or n8n.

Plans and prices

Prices are in euros, billed monthly, and the unit is the verified prospect: "a company in the French register with a checked email and a named person to write to." Finding and enriching companies is never metered.

• Free, €0 with no card: 25 verified prospects a month, 10 emails a day and 200 a month, 100 marketing contacts, 30 AI assistant messages, sending from a Mailbase address, 1 user and 1 workspace.
• Starter, €9 a month (€0.030 per verified prospect): 300 prospects, 50,000 emails a month, a daily limit of 10,000, 5,000 marketing contacts, 500 AI messages, your own verified domain, 2 users and 3 workspaces.
• Growth, €29 a month (€0.029 per prospect): 1,000 prospects, 150,000 emails, a daily limit of 30,000, 25,000 marketing contacts, 2,000 AI messages, A/B testing with an automatic winner, deliverability analytics, 5 users and 10 workspaces.
• Scale, €79 a month (€0.020 per prospect): 4,000 prospects, 500,000 emails, a daily limit of 100,000, 100,000 marketing contacts, 10,000 AI messages, priority deliverability support, a dedicated IP option, 15 users and unlimited workspaces.

The comparison table also lists a domain included for the first year. Transactional email is priced by the plan's included volume, while marketing email uses the contact limit plus the monthly send cap. A prospect pack adds 500 verified prospects for €19, one-time, on any plan, and those credits never expire. The Bring-your-own-useSend plan costs €5 a month and includes campaigns, the inbox, A/B testing, analytics, the API, 5 users and 25 verified prospects a month; sending volume is limited only by your own instance. When you hit an email limit, sending pauses for the rest of the cycle rather than billing overage, and when prospects run out, verification pauses while discovery keeps running.

Who it suits

Mailbase fits a founder, freelancer or small sales team selling to French small businesses, from plumbers in Gironde to accountants in Lille, who wants the list, the first drafts and the follow-up handled with approval at every step. The free plan is enough, in the company's words, "to run one real target end to end." Developers get a clean transactional API and MCP access, and teams that already run useSend can keep delivery on their own infrastructure for €5 a month. For prospects outside France, the discovery engine does not apply, though the rest of the workspace works for any audience.