MultiMail adds a dedicated email API and human-approval layer to Zapier AI automations so agents can send, read, and reply without skipping review.
Zapier AI Actions lets you expose Zap automations as callable tools for AI assistants and agentic workflows. When one of those tools involves email — notifying a lead, replying to a support ticket, escalating an alert — the generic Zapier Gmail or Outlook action offers no audit trail, no gating, and no per-tenant policy control.
MultiMail fills that gap. You configure a Zap that calls MultiMail's REST API, expose it as a Zapier AI Action, and your assistant gains a send_email or reply_email tool that routes through MultiMail's oversight layer. Outbound messages queue for human approval under gated_send mode before any bytes leave the server.
Inbound email works the same way in reverse: MultiMail fires a webhook into a Zapier catch hook when mail arrives, giving the AI assistant structured data — sender, subject, body, thread ID — without exposing raw IMAP credentials to your automation stack.
Zapier's native email steps send immediately. MultiMail's gated_send mode holds outbound messages until a human approves via the dashboard or the POST /v1/oversight/decide endpoint, with a full audit trail attached to every decision.
Different Zaps warrant different risk tolerance. A CRM follow-up Zap can run under monitored mode while a payment-dispute Zap stays on gated_all. Oversight mode is set per mailbox, not per run, so policies survive Zap edits.
MultiMail webhooks emit normalized JSON — thread_id, sender reputation, tag classifications — that Zapier filter and path steps can branch on directly, without a parsing code step.
If you run Zaps on behalf of multiple clients, each client gets their own MultiMail mailbox and API key. Email never crosses tenant boundaries, which matters for GDPR data-processor obligations.
MultiMail webhooks fire on delivery, bounce, and approval events. A Zap path step can branch on approval_granted versus approval_denied and continue automation accordingly, without polling.
No code, no dashboard. Paste this to your AI agent — it connects MultiMail, creates an inbox, and builds the flow for you.
Sign up at multimail.dev and create a mailbox for your Zapier automation (e.g., crm-agent@yourco.multimail.dev). Copy the mm_live_... API key from the dashboard — you will add this as a Zapier environment variable or secret in the next step.
In Zapier, go to your account settings and add MM_API_KEY as an environment variable (Zapier Code steps can read process.env values). For team Zaps, use Zapier's Secret Manager so the key is not stored in plain text inside Zap steps.
Create a new Zap with a Webhook or AI Action trigger. Add a Code (JavaScript) step that calls POST https://api.multimail.dev/v1/mailboxes/{mailbox_id}/send using the API key from process.env.MM_API_KEY. Map the trigger fields (to, subject, markdown) into the request body. Oversight (gated_send) is set on the mailbox at creation, not per send.
In the Zapier AI Actions dashboard, expose this Zap as a callable tool. Give it a clear name (e.g., 'Send CRM follow-up email') and description so the AI assistant can select it correctly. The action takes recipient, subject, and body as inputs and returns message_id.
In the MultiMail dashboard under Settings > Webhooks, add your second Zapier catch hook URL as the approval event endpoint. This Zap receives approval.granted and approval.denied events so you can update downstream systems (CRM records, Slack threads) without polling.
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