Flowmails vs Resend
Developer-first SaaS transactional email. 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
Resend's free tier caps at 100 emails/day and 3,000 / month; paid plans start at $20 / month for 50,000 emails. Flowmails' Base plan is $0 forever; Pro is $9.9 / month and Enterprise is $39.9 / month, regardless of volume (Cloudflare's own usage is billed by Cloudflare directly).
Setup shape
Resend is a hosted API — sign up, verify your domain via DNS, call the API. Flowmails connects your domain provider over OAuth and runs one shared mail worker for every tenant; outbound goes to Resend or Cloudflare Email Sending, whichever you pick per domain.
Best fit
Resend: zero-ops teams who want the fastest possible first-send and outbound only. Flowmails: teams that need inbound mail, route tables and an agent-usable API alongside outbound, on one connection.
Feature matrix
Resend vs Flowmails, line by line.
| Feature | Resend | Flowmails |
|---|---|---|
| Data residency | Resend multi-tenant database | Flowmails' own storage, scoped by domain id |
| Inbound webhook | Yes | Yes |
| Hosted mail worker | No — send only | Yes — one shared worker, inbound + outbound |
| Custom-domain setup | DNS only | Cloudflare Email Routing auto-configured |
| Per-email pricing | Yes (above plan cap) | No (your provider bills you directly) |
| Audit / export | API only | API export, documented schema |
Integration parity
SDK and runtime compatibility.
Both expose a Node SDK and a REST API. Resend's SDK runs in any runtime; Flowmails' SDK is the same shape and additionally targets Cloudflare Workers, Bun, and Deno out of the box.
Migrating
How to switch from Resend to Flowmails.
Point your domain's routing at Flowmails
If your domain is already on Cloudflare, skip this step. Otherwise the domain needs an active provider zone — Cloudflare is the routing provider we support today, and the provider SPI is open to others, so more are on the way.
Connect Flowmails with an OAuth sign-in
Flowmails connects to your provider over OAuth — no API token is pasted and none is stored. The grant has a bounded lifetime, and Flowmails provisions the shared mail worker, the storage and the route table for you.
Swap the sending path
Replace `Resend` SDK calls with the Flowmails SDK, point it at the new API key, and ship templates as plain HTML / text — Resend's templates are not locked to its own renderer.
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