Mailgun automation · Built for developers

Event-driven email automation on Mailgun

Mailgun is rock-solid for sending - but automation, contacts, and templates still ask you to bring your own tooling. FlowingMail plugs directly into your Mailgun domain and adds a startup-friendly automation builder with a generous free tier, a typed REST API, and zero markup on sending.

Why FlowingMail

Why run FlowingMail on Mailgun

You already have Mailgun for transactional + bulk sending. Stop duct-taping together mailing lists and cron jobs - use a real automation builder on top of it. Email drives $36–$45 per $1 spent (DMA, 2026); the missing piece for most Mailgun teams is just the workflow layer.

Bring your own Mailgun API key - US and EU regions both supported
Startup-friendly flat pricing - no per-contact fees, zero markup on sending
Generous free tier (5 flows, 25,000 contacts, 2 senders) covers early testing
Event-driven: versioned REST API with OpenAPI spec, built for developers triggering flows from code
Dedicated IPs and IP pools honoured automatically
Keep Mailgun Routes for inbound, add FlowingMail for outbound automation

Capabilities

Features Mailgun doesn't ship with

Visual automation canvas

Triggers, delays, conditions, filters, and sends - all as drag-and-drop nodes.

Contact segmentation

Groups + attribute-based filters. Reuse segments across campaigns and flows.

Template editor

HTML + text templates with live preview and {{ variable }} substitution (fallbacks supported).

Analytics dashboard

Real-time sent / open / click / bounce / complaint metrics per campaign and per flow.

Contact management

CSV import, API push, global unsubscribe list - synced with Mailgun's suppression list.

REST trigger

One API call starts a workflow. Trigger from any backend - Node, Python, Go, PHP.

How it works

From Mailgun to live automation

Connect Mailgun

Paste your Mailgun API key and pick the region (US or EU). FlowingMail validates access and lists your domains.

Design the flow

Pick a trigger, branch on conditions, add delays, drop send-email nodes tied to your Mailgun sender.

Activate & watch events

FlowingMail registers a webhook on your Mailgun domain. Events stream in, populate analytics, and drive branch conditions.

Integration

Trigger a Mailgun-backed flow

Your backend calls FlowingMail; FlowingMail calls Mailgun. You can skip every retry/queue/template concern and get delivery events back through the same webhook you were going to configure anyway.

# $FLOW_ID is the flw_xxx ID from the dashboard.
curl -X POST "https://api.flowingmail.com/v1/flows/$FLOW_ID/trigger" \
  -H "Authorization: Bearer $FLOWINGMAIL_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "contactId": "cnt_abc123",
    "variables": { "trial_ends": "2026-05-01" }
  }'

FAQ

Mailgun automation - FAQ

No. Your Mailgun account stays exactly as it is - same domains, same IPs, same billing. FlowingMail is a marketing-automation layer that talks to Mailgun via your API key.

Yes. FlowingMail supports both the US (api.mailgun.net) and EU (api.eu.mailgun.net) endpoints. You pick the region when connecting a Mailgun sender.

When you connect a Mailgun sender, FlowingMail can auto-register webhooks for delivered / opened / clicked / permanent_fail / temporary_fail / unsubscribed / complained. You can also add them manually.

No. FlowingMail sends via the Mailgun API - whichever IP pool is assigned to your domain is used for delivery. Rate-capped sends inside flows let you warm up new IPs gradually.

Yes. Unsubscribes, bounces, and complaints are written to Mailgun's suppression list, and existing suppressions are respected on every FlowingMail send.

Yes. Workflows, templates, and contacts don't care which provider you use. Add a SES or Resend sender, repoint the send actions, and you're done.