Email and newsletters decision
SMTPfast
A small engineering team or single experienced developer can reproduce the core transactional API, SMTP bridge, event tracing and domain verification in a few weeks using SES and open-source projects; the hosted product's extra polish, agent integrations, and support are the main reasons to keep paying.
Visit website↗Built by Bobby Iliev, who ships 4 products in this index
$9/mo
$108/yr
Read off the official pricing page.
$100one-off160 h to build
$2.5/mo6 h/mo upkeep
On cash alone, building overtakes the subscription at 2 seats.
Open-source builds that already do this
Every project below is open source and already does this job today. Fork one, self-host it, or take the parts you need - the build prompt further down assumes an empty file, and this is the shortcut past that. Licences differ; check the one on each card before you ship. All SMTPfast alternatives, with the arithmetic →
What a replacement has to do
- Accept a JSON REST request to send an email, hand it to a relay (SES), record and surface delivery events, and surface live logs and webhooks for downstream consumers.
What it still won’t have
- Hosted MCP server, OpenAPI/Claude skill conveniences for agent integrations
- Turnkey deliverability tooling and any carrier-specific optimizations
- Dedicated support, SLA and priority queue from the vendor
- Prebuilt broadcast UI with contact-segmentation and double-opt-in flows
What remains hard
- Product polish and ongoing maintenance
First-year cost
Keep paying
Paying is—cheaper in year one.
On cash alone, building overtakes the subscription at 2 seats.
Money you would actually spend
Time you would spend
—
What you would spend
What we assumed
The verdict above measures whether you could build it. This one is only about money.
Runnable build prompt
Build a minimal transactional email service: implement a Node.js (Express) backend, Postgres for event storage, AWS SES as the relay, and a lightweight web UI. Scope in: REST POST /api/v1/emails that enqueues sends to SES, an SMTP bridge (auth via API key) for legacy clients, event ingestion of SES bounces/deliveries/opens into Postgres, HMAC-signed webhook delivery, a Server-Sent Events /live-tail endpoint for realtime logs, and a domain verification page that checks DKIM/SPF DNS records. Out of scope: advanced broadcast composer, contact segmentation UI, hosted MCP/Claude integrations, and multi-tenant billing. Include API key auth, error handling, unit/integration tests for the send and webhook flows, and deploy scripts (Docker + single small VPS or managed service).
How we checked
How the score was reached
- Partly verdict base52
- An open-source build was found+5
- 5 cited sources+3
- Price verified on pricing page+3
- 3/3 assessment runs agreed+4
- Evidence score67
The base comes from the verdict. Everything under it is a check that either happened or did not, and each one is a fact frozen in this record rather than a judgement made at render time - so the same evidence always produces the same number.
How scoring works →Cited sources · 5
Every page the run actually retrieved.
- official productSMTPfast - Email API for Developers
- official pricingPricing - SMTPfast
- official docsAPI Documentation - SMTPfast
- open sourceNotifuse/notifuse
- open sourceBillionmail/BillionMail
Integrity checks
What held up, and what did not.
