Flowmails vs Mailgun
Developer-oriented transactional email (Sinch). This page is a side-by-side on the parts that matter when you're considering a switch — data residency, pricing, and the parts of each stack that show up in a real migration.
At a glance
Three sentence compare.
Pricing shape
Mailgun's free tier is 100 emails/day for 1 month; paid plans start at $15 / month for 10,000 emails. Flowmails' Base plan is $0; Pro is $9.9 / month.
Setup shape
Mailgun is hosted — sign up, verify domain, call the API. Flowmails deploys into your Cloudflare account.
Best fit
Mailgun: teams that need its deliverability tooling (inbox placement, validation) and its email-list / routes products. Flowmails: teams that want self-hosted email without the breadth.
Feature matrix
Mailgun vs Flowmails, line by line.
| Feature | Mailgun | Flowmails |
|---|---|---|
| Data residency | Mailgun multi-tenant (Sinch) | Your D1 in your Cloudflare account |
| Inbound routing | Yes (Routes product) | Yes (route tables in your D1) |
| SMTP relay | Yes | No |
| Email validation | Yes (paid add-on) | Not bundled |
| Mailing lists | Yes | No (transactional only) |
| Per-email pricing | Yes (volume tiers) | No |
Integration parity
SDK and runtime compatibility.
Mailgun exposes both an HTTP API and an SMTP relay. Flowmails is REST-only. SDK-wise, the surface areas are similar (send / receive / stats).
Migrating
How to switch from Mailgun to Flowmails.
Decide whether you need Mailgun's optimisation / validation products
If your team depends on Mailgun's inbox placement reports or email validation, plan for those independently — Flowmails doesn't bundle equivalents. If you only ever used Mailgun for send / receive, the migration is straightforward.
Move the domain to Cloudflare
Same prerequisite as every other self-hosted-on-Cloudflare flow: the zone must be on Cloudflare for Email Routing + Email Services to bind to it.
Replace the SDK
Swap Mailgun SDK calls for Flowmails SDK calls. Templates are plain HTML, so the renderer is unchanged. If you used Mailgun's inbound routes, port them into Flowmails' route tables (literal matchers, not regex).
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