SMTPfast vs Buttondown.

Product email infrastructure instead of a newsletter publishing tool.

Buttondown is a focused newsletter product for writers and small teams. SMTPfast is not a publishing CMS; it is an API/SMTP email platform for transactional sends, broadcasts, forms, webhooks, logs, domains, and suppressions.

SMTPfast

Email sending and SaaS operations pricing.

Buttondown is a publishing workflow; SMTPfast is an email infrastructure workflow.

Buttondown

Newsletter/subscriber pricing.

Best for: Writers and small teams publishing newsletters.

What SMTPfast adds

The useful differences for teams evaluating Buttondown.

Transactional API and SMTP relay.
Delivery events, webhooks, live logs, and suppressions.
Batch sends, idempotency, attachments, and scheduling.
Domain verification and custom MAIL FROM operations.

Short verdict

Choose Buttondown if the job is newsletter publishing. Choose SMTPfast if the job is product email infrastructure with API/SMTP sends, logs, webhooks, domain verification, suppressions, and lightweight broadcasts.

Try SMTPfast free

Feature	SMTPfast	Buttondown
Pricing model	Simple volume plans	Subscriber/newsletter tiers
Public free tier	3,000 emails/month	First 100 subscribers free
API & Sending
REST API
Resend-compatible payloads
SMTP relay
Batch sending	100/request
Idempotency keys
Inline images (cid) and automatic plain text		Not published
Customer webhooks
Share links for sent emails		Not published
Marketing & Audience
Broadcast campaigns
Signup forms
Broken link check before sending		Not published
Workflow automation	Planned	Limited
Dynamic segments	Planned	Basic
Hosted templates	Planned
Deliverability & Safety
DKIM/SPF/DMARC guidance
Custom MAIL FROM
Suppression management
Live event tail
Warmup and abuse controls
Platform Model
Inbound email	Paid plans
MCP server for AI agents		Not published
Terraform provider	Official	Not published
Agent skill for coding assistants	Official	Not published
API key scopes	Per key	Not published
Open source	Evaluating
Self-hostable	Evaluating
Team members and roles	Paid plans	Not published
No per-seat pricing

Choose Buttondown if

You publish newsletters and want archives, editor UX, and subscriber management.
A writer or editor owns the workflow.
Transactional email is not part of the requirement.

Choose SMTPfast if

Your emails come from your application rather than from you writing them.
You need an API, an SMTP endpoint and webhooks, which a newsletter tool is not built to give you.
Broadcasts are one thing your product does, not the whole of what it does.

Migration checklist

1Export subscribers and unsubscribe state from Buttondown.
2Create an SMTPfast account and generate an API key with email:send scope.
3Add and verify your sending domain with DKIM, SPF, DMARC, and MAIL FROM records.
4Send a low-volume test message and confirm events appear in the SMTPfast logs.
5Move production traffic gradually while watching bounces, complaints, and suppressions.
6Rebuild only the broadcast flows that need API/SMTP integration.

Frequently asked questions.

Is SMTPfast better than Buttondown?

Buttondown is stronger for newsletter publishing. SMTPfast is stronger for product-triggered API/SMTP email, delivery operations, and SaaS email infrastructure.

When should I still choose Buttondown?

Choose Buttondown when its core strength matches your team: Writers and small teams publishing newsletters. SMTPfast is a better fit when you want a developer-first SES-backed API with queues, webhooks, tracking, suppressions, and a focused dashboard already handled.

How hard is it to migrate from Buttondown to SMTPfast?

Most migrations start with domain verification, a test API key, and one low-risk transactional email path. Resend-compatible payloads are especially quick to move; older providers may require mapping template, webhook, and suppression behavior.