Event-driven email automation for developers
Most automation platforms bundle tooling with delivery and charge per contact. FlowingMail unbundles them: a startup-friendly automation builder on top of your own provider (Resend, SendGrid, Mailgun, Amazon SES, or SMTP), with a generous free tier and flat pricing instead of per-contact billing.
Automation that works with your stack
Keep the sender reputation, domains, and provider you already trust. Add a real automation builder on top. Automated emails convert 2,361% higher than broadcasts (Omnisend, 2026) - the only reason most teams don't ship them is the tooling tax. FlowingMail removes that tax.
- Bring your own provider - Resend, SendGrid, Mailgun, Amazon SES, or SMTP
- Startup-friendly flat pricing - no per-contact or per-email fees
- Generous free tier: 5 flows, 25,000 contacts, 2 senders, forever
- Built for developers: versioned REST API, idempotency keys, versioned templates
- Event-driven: trigger flows from your app via a single POST
- Self-hostable flow worker for compliance-regulated workloads (HIPAA, PCI, on-prem)
What a real email automation platform needs
A minimum viable automation stack - built once, reusable across every campaign and flow.
Visual workflow builder
Canvas-based editor with triggers, conditions, delays, filters, and send actions. Zoom, pan, hotkeys - built for serious flows.
Triggers from anywhere
Contact created, added to group, REST webhook, schedule, or cron. Forward Stripe/Clerk/Segment events directly.
Branching & conditions
If/else branches on contact attributes, group membership, engagement, or custom event data.
Delays & time windows
Relative delays (2 days after), absolute timers (next Tuesday 9am), timezone-aware send windows per contact.
Segmentation
Filter contacts on any attribute combination, reuse segments across campaigns and flows, and test segments live.
Per-flow analytics
See completion rate, branch distribution, and deliverability for every node in every flow.
From zero to automated in four steps
Connect your provider
Paste an API key or SMTP credentials. Verify domains if needed.
Import contacts
CSV upload, API push, or sync from your app. Attributes + groups from day one.
Build a flow
Drag triggers, delays, conditions, and send actions onto the canvas. Preview before activating.
Measure & iterate
Watch deliverability, opens, clicks, and branch distribution with live campaign and flow metrics.
Trigger flows from your application
One REST endpoint drives everything: new signups, checkout events, trial expirations, re-engagement - all shaped by the same workflow canvas.
# $FLOW_ID is the flw_xxx ID from the dashboard.
# contactId is the cnt_xxx for the contact entering the flow -
# create it first via POST /v1/contacts or /v1/contacts/batch.
curl -X POST "https://api.flowingmail.com/v1/flows/$FLOW_ID/trigger" \
-H "Authorization: Bearer $FLOWINGMAIL_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"contactId": "cnt_abc123",
"variables": { "plan": "pro", "country": "US" }
}'Email automation - FAQ
Email automation is the use of pre-defined rules and workflows to send emails based on contact behavior or attributes - for example, a welcome email when someone signs up, a reminder when a trial is about to expire, or a drip of product tips across the first 30 days. It replaces manually sending the same emails over and over.
Traditional platforms bundle sending, deliverability, and pricing into a single product. FlowingMail separates the tooling from delivery: you plug in your own provider (Resend/SendGrid/Mailgun/SES/SMTP), we run the workflow engine, and there's no per-contact markup. That means you keep your sender reputation and pay transparent pricing.
Yes. FlowingMail doesn't artificially split the two - receipts, welcome emails, onboarding drips, broadcasts, and re-engagement all live in the same canvas. You can bind different flows to different senders if you want to isolate traffic on separate API keys or provider accounts.
It works for both. Transactional use cases (password resets, receipts, notifications) typically skip delays and just need a trigger + single send action. Marketing flows use longer sequences with branching logic and delays.
Not for the workflow canvas itself. You do need a single API call (or webhook) to trigger flows from your application - that's a one-liner in any language. Templates support {{ variable }} placeholders with no code.
Deliverability is owned by your email provider (Resend/SendGrid/Mailgun/SES), not FlowingMail. That's actually an advantage: you control your domain authentication (SPF/DKIM/DMARC), your IPs, and your sender reputation - without a shared-pool ESP diluting it.
Explore more
Automation built on top of Amazon SES.
Modern automation on top of the Resend API.
Replace SendGrid Marketing Campaigns.
Workflows for Mailgun US / EU accounts.
How branching, delays, and conditions work in practice.
Full comparison against Mailchimp's automations feature set.