Resend automation · Built for developers

Event-driven email automation on Resend

Resend is the best email API for developers. FlowingMail adds the automation builder: visual workflows, contact segmentation, campaigns, and analytics - on top of your existing Resend domains and audiences. Startup-friendly pricing, generous free tier, zero markup on sending.

Why FlowingMail

Why pair Resend with FlowingMail

Resend is a transactional API with a contacts table bolted on. FlowingMail adds a real automation builder on top - without locking you into a new ESP. Automated emails generate 320% more revenue than broadcasts (Campaign Monitor, 2026); the only thing stopping most teams from shipping them is the tooling.

Bring your own Resend API key - your domains, your audiences, your reputation
Generous free tier (5 flows, 25,000 contacts) pairs perfectly with Resend's free 3k/mo
Paste rendered HTML from any template engine - FlowingMail doesn't care how it was produced
Event-driven: trigger flows from your code with a single POST request
No per-contact markup - flat pricing from $14/mo
Switch to SES or Mailgun later without rewriting a single flow

Capabilities

What FlowingMail adds to Resend

Drag-and-drop workflow editor

Compose triggers, delays, conditions, and send actions visually. Branch on contact attributes or event data.

Segmentation & groups

Filter contacts by any attribute combination. Re-usable segments across campaigns and automated flows.

Campaign scheduler

One-off broadcasts with send-time windows and timezone-aware scheduling.

Deliverability analytics

Ingests Resend webhook events (delivered, opened, clicked, bounced, complained) and pivots them per campaign.

Trigger flows from your app

One REST endpoint to start a flow. Forward Stripe, Clerk, or your own events directly into automation.

Suppression & unsubscribe handling

List-Unsubscribe headers, built-in unsubscribe pages, global suppression list - all synced to Resend.

How it works

From Resend API key to live automation

Connect Resend

Paste your Resend API key. FlowingMail verifies the key, lists your domains, and imports your audiences.

Build a flow

Pick a trigger (Signup, Added to Group, API event), map conditions, drop send-email actions bound to your Resend domain.

Go live

Activate. Sends go through Resend, events stream back, and every open/click lands in your analytics dashboard.

Integration

Trigger Resend-powered flows from anywhere

Send one HTTP request - FlowingMail handles templating, segmentation, delays, and the Resend API call.

# $FLOW_ID is the flw_xxx ID from the dashboard.
# contactId is the cnt_xxx for the contact you want to enter into the flow.
curl -X POST "https://api.flowingmail.com/v1/flows/$FLOW_ID/trigger" \
  -H "Authorization: Bearer $FLOWINGMAIL_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "contactId": "cnt_abc123",
    "variables": { "plan": "pro" }
  }'

FAQ

Resend automation - FAQ

No. FlowingMail uses your Resend account for delivery. You keep your verified domains, your DKIM records, your Resend dashboard, and your billing relationship with Resend. FlowingMail adds the marketing-automation layer on top.

Yes. Paste the rendered HTML into a FlowingMail template - whether it came from React Email, MJML, Handlebars, or hand-crafted markup. Variable placeholders use {{ variable }} syntax with optional fallback values.

FlowingMail registers a webhook on your Resend account. Delivered / bounced / opened / clicked / complained events stream into FlowingMail in real time and populate campaign analytics and contact timelines.

Resend's pricing is unchanged - you pay them per email as before. FlowingMail is billed separately at a flat $0 / $14 / $42 per month (Free / Startup / Business - Business includes 3 seats with purchasable extras). No markup on email volume.

Yes. Workflows, templates, and contacts are provider-agnostic. Swap the sender on any send-email node to change provider - no rewrite required.