Looking for a SendGrid alternative you can host on your own Cloudflare account?
Self-hosted on Cloudflare with no per-email pricing and a smaller surface area — Flowmails is what you ship when SendGrid's feature breadth has become overkill for your actual workload.
SendGrid is a great product — it's where most teams land the first time they need transactional email that "just works." But as your stack matures, the calculus often shifts: data residency requirements, predictable cost at higher volumes, and the desire to keep the email control plane on the same host as the rest of your infrastructure.
Flowmails is what you ship when those are the things you've started to care about. It runs on Cloudflare — the same one your Workers, R2 buckets, and Pages deployments already live in — and stores your inbox, outbox, and routing rules in your own D1. There is no per-email fee on top of Cloudflare's own pricing; the platform subscription is what you see on the /price page.
SendGrid's free tier is 100 emails/day forever; paid plans start around $15 / month for 50,000 emails and scale to six-figure annual contracts at high volume. Flowmails' Base plan is $0; Pro is $9.9 / month.
SendGrid is a hosted API — sign up, verify a sender domain via DKIM, call the API or SMTP relay. Flowmails deploys into your Cloudflare account and provisions its own primitives.
SendGrid: large teams that need its dedicated deliverability consultants, dedicated IPs, and sub-user management. Flowmails: teams that want a leaner, self-hosted stack.
SendGrid ships an SMTP relay in addition to its REST API, so legacy apps can keep talking to it. Flowmails speaks HTTPS REST only — there is no SMTP relay on the Flowmails side. If you depend on SMTP for legacy clients, keep SendGrid (or a relay) for that surface.
Highlights
What Flowmails does differently
Data residency
Your D1 in your Cloudflare account
Inbound parse webhook
Yes
SMTP relay
No (REST only)
Dedicated IP
No (Cloudflare-managed shared IPs)
Sub-user management
Single account per Cloudflare zone
Per-email pricing
No
Migration
How to migrate from SendGrid to Flowmails
Audit which SendGrid features you actually use
If you depend on dedicated IPs, sub-user management, or the SMTP relay, map those to a Flowmails equivalent (or decide they aren't required). Flowmails is intentionally a smaller surface.
Move the domain to Cloudflare if it isn't already
Flowmails provisions Email Routing and Email Services on a Cloudflare zone. If your DNS lives elsewhere, transferring the zone to Cloudflare is the standard prerequisite.
Swap send traffic to the Flowmails SDK
SendGrid SDK calls map to Flowmails SDK calls. Update the auth (Flowmails API key instead of SendGrid API key), update the from-address to your verified zone, and ship. Templates port as plain HTML.
FAQ
Common questions about switching from SendGrid
Other alternatives