
MailShrine
Developer APIEmail that ships inside your product.
One shared MailShrine login. Open the Developer API dashboard to manage keys, domains, webhooks, and SMTP — REST, SDKs, CLI, and more. 3,000 free emails every month on Sandbox (soft 300/day). Paid packs never expire — 1 credit = 1 send. USD + NGN.
Why Developer API
Send email from your product on the same MailShrine account
Not a separate ESP login — keys, domains, SMTP, webhooks, templates, and Stella live next to Email Marketing, Business Email, and Lead Generator. 1 credit = 1 accepted send. Sandbox gives you free monthly emails; paid packs never expire. Ship with REST or SMTP, listen to eight delivery events, and wire Zapier/Make when you are not writing backend code yet.
REST + SMTP
HTTP send for new apps; relay for tools that already speak mail.
Eight events
Delivered through failed — signed webhooks your backend can trust.
Six SDKs + CLI
Node, TypeScript, Python, Go, Ruby, PHP — plus terminal checks.
Stella inside
Ask how to ship a path; approve before she creates keys or hooks.
Connect your stack
3,000 emails / monthDeveloper API
3,000 free emails every month on Sandbox (soft 300/day). Paid packs never expire — 1 credit = 1 send. USD + NGN. Send email from your product on the same MailShrine account. REST, SDKs, CLI, webhooks, SMTP, Shopify and no-code — plus Stella, the in-product AI that answers from our docs and can create keys or webhooks after you approve.
In-product AI
Meet Stella
Not a generic chatbot — Stella is your MailShrine build partner. Ask how to ship a send path; get steps, snippets, and safe actions you confirm before they run.
Product-trained
Answers from MailShrine DevAPI knowledge — keys, domains, SMTP, webhooks.
Can take action
Proposes creating keys & webhooks. You approve — then it runs.
Role-aware
Viewers stay read-only. Chat never burns your send credits.

01
REST API
Send, templates, and events over HTTPS — any language that can call an API with a Bearer key.
02
Official SDKs
Node, TypeScript, Python, PHP, Go, and Ruby samples so you can ship without wiring every request by hand.
03
CLI
Login with your API key, send a test, and check usage from the terminal or CI.
04
Webhooks
Push delivered, bounce, complaint, open, and click events into your product with signed payloads.
05
SMTP relay
Point existing apps at MailShrine when you already speak classic mail protocols.
06
No-code & apps
Zapier, Make, n8n, Shopify, and more — connect without rebuilding your stack.
api/v1/emails/send
live · open beta
// Authorization: Bearer ms_live_…POST /api/v1/emails/send{ "to": "user@acme.com",
"from": "orders@yourdomain.com",
"subject": "Welcome aboard"
}SDK languages
Platforms & tools
01 — Security
API keys with scopes you control
Create keys in the dashboard, copy the secret once, and lock each key to the scopes your app needs — send, templates, webhooks, domains, or relay. Rotate or revoke without redeploying the whole product.
- ✓Secrets shown once at creation — prefixes only after that
- ✓Scopes: send.email, templates, webhooks.manage, domains.manage, relay.read
- ✓Audit trail when keys are created, rotated, or revoked
Dashboard → API Keys

02 — Deliverability
Domain Auth that protects inbox placement
Add your sending domain, publish SPF, DKIM, and DMARC, then verify in one place. From addresses must use a verified domain — the same discipline production email teams expect.
- ✓Clear DNS records to copy into your registrar
- ✓Verify status in the dashboard before first send
- ✓Works with the suite reputation story, not a separate silo
Dashboard → Domain Auth

03 — Send
REST send that costs one credit per accepted email
POST /emails/send with a Bearer key. Subject and text/html or a templateId with merge data. Sandbox soft-caps protect free usage; paid packs never expire. Try the same call live in the Playground.
- ✓1 credit = 1 accepted send
- ✓Templates with {{merge}} fields
- ✓Same wallet model as the rest of MailShrine
Docs · Playground · SDKs

04 — SMTP
SMTP relay for apps that already speak mail
Point WordPress, legacy CRMs, or internal tools at MailShrine relay credentials. Host, port, username, and password live on the SMTP Relay page — rotate passwords when you need to.
- ✓TLS on 587 (SSL alternate 465)
- ✓Username and password assigned by MailShrine
- ✓No need to rewrite every SMTP client overnight
Dashboard → SMTP Relay

05 — Events
Signed webhooks for delivery truth
Register an HTTPS URL and choose which delivery events you care about. MailShrine signs every payload so your backend can trust opens, clicks, bounces, and failures.
- ✓HMAC signature on the raw JSON body
- ✓Ping / live status for each endpoint
- ✓Eight event types — pick defaults or select all
Dashboard → Webhooks

Listen to every signal
8 delivery events
Choose defaults (Delivered, Bounced, Opened) or select all — each payload is HMAC-signed.
01
Delivered
email.delivered
Reached the mailbox provider
02
Bounced
email.bounced
Address rejected or undeliverable
03
Complained
email.complained
Marked as spam
04
Opened
email.opened
Recipient opened the email
05
Clicked
email.clicked
Link in the email was clicked
06
Rejected
email.rejected
Blocked before send
07
Delayed
email.delayed
Temporary delivery delay
08
Failed
email.failed
Send or rendering failed
06 — No-code
Zapier, Make, n8n, and more — without a backend rewrite
Connect the apps your ops team already runs. Send transactional mail and react to delivery events across Zapier, Make, n8n, Webflow, WordPress, and Shopify.
- ✓Zapier & Make connected flows
- ✓WordPress plugin and Shopify paths
- ✓Same API key scopes as your custom code
Dashboard → No-Code Apps

Zapier
Send email and react to delivery events across 5,000+ apps.
Make.com
Visual scenarios — HTTP send + webhook catch.
n8n
Open-source automation with HTTP Request nodes.
Webflow
Form submissions → confirmation emails.
WordPress
Contact forms and wp_mail through MailShrine.
Shopify
Order confirmations via Flow or custom apps.
07 — Playground
Call live REST endpoints before you ship
Pick an endpoint, edit the JSON, and send with your suite session or an API key. Inspect the real response — stats, templates, single send, or bulk.
- ✓GET /v1/stats, templates, POST send & bulk
- ✓Suite session or API key auth
- ✓Reset sample payloads in one click
Dashboard → API Playground

08 — SDKs
SDKs for the languages you already ship
Open-source, strongly typed clients for Node.js, TypeScript, Python, Go, Ruby, and PHP — plus a CLI for quick terminal checks.
- ✓Node.js · TypeScript · Python · Go · Ruby · PHP
- ✓Install from the suite repo; works on your computer
- ✓CLI: install, login, send test, check usage
Dashboard → SDK Libraries


09 — Templates
Save subject and body once — send with templateId
Author {{merge}} templates in the dashboard, then send with templateId and data from your app. Marketing, ecommerce, and transactional shapes in one place.
- ✓{{variables}} in subject and body
- ✓Reuse across REST and bulk send
- ✓Search and manage from Intelligence → Templates
Dashboard → Templates

10 — Stella
Stella — your in-product developer partner
Ask Stella how to achieve a goal on MailShrine. She answers from product knowledge, proposes step-by-step plans, and can create keys or webhooks only after you approve — viewers stay read-only.
- ✓Grounded in Developer API docs and flows
- ✓Confirm-before-write for mutating actions
- ✓Does not spend email send credits to chat
Dashboard → Stella

Pricing
Same packs as the dashboard
Sandbox refills monthly. Paid packs never expire. 1 credit = 1 accepted send — USD and Naira on the same cards you see after login.
Sandbox
3,000 credits/month
≈ 3,000 emails
- 3,000 emails every month
- Soft cap 300 emails/day
- Unlimited domains
- API + SMTP relay
- Refills every month
Relay
50,000 credits
≈ 50,000 emails
- 50,000 emails
- $2.30 / 10k
- Credits never expire
- Unlimited domains
- API + SMTP relay
Dispatch
100,000 credits
≈ 100,000 emails
- 100,000 emails
- $2.30 / 10k
- Credits never expire
- Unlimited domains
- Priority support
Signal
250,000 credits
≈ 250,000 emails
- 250,000 emails
- $2.30 / 10k
- Credits never expire
- Unlimited domains
- Priority support
Cascade
500,000 credits
≈ 500,000 emails
- 500,000 emails
- $2.30 / 10k
- Credits never expire
- Unlimited domains
- Priority support
Orbit
1,000,000 credits
≈ 1,000,000 emails
- 1,000,000 emails
- $2.30 / 10k
- Credits never expire
- Unlimited domains
- Priority support
16 — Price comparison · USD
Where MailShrine sits on send price
49+ email APIs and ESPs. Pick a volume. We rank the lowest published per-email first. MailShrine is pay-as-you-go only — no monthly send plan — at a flat $2.30 / 10k, and paid packs never expire. Educational estimates, not live quotes.
UsAt 50,000 emails, MailShrine is #1 in this list — Relay · ~$11.50 for 50,000 · $0.230 / 1k. Sandbox is 3,000 emails every month · soft 300/day.
50 of 50 companies
Price table · 50,000 emails
| Company | Pricing | Price at this size | Free allowance |
|---|---|---|---|
| MailShrineUs | Pay as you go | Relay · ~$11.50 for 50,000 · $0.230 / 1k | Sandbox · 3,000 emails every month · soft 300/day |
| Scaleway TEM | Pay as you go | ~$12.50 · $0.250 / 1k | Limited free tier |
| Yandex Postbox | Pay as you go | ~$15.00 · $0.300 / 1k | Limited free |
| Selectel Cloud Email | Pay as you go | ~$20.00 · $0.400 / 1k | Trial |
| Elastic Email | Pay as you go | ~$40.00 · $0.800 / 1k | Limited free |
| ZeptoMail | Pay as you go | ~$45.00 · $0.900 / 1k | Free credits on signup |
| Netcore Email API | Pay as you go | ~$47.50 · $0.950 / 1k | Trial |
| SMTP2GO | Pay as you go | ~$50.00 · $1.00 / 1k | 1,000 emails/mo free |
| Unisender Go | Pay as you go | ~$50.00 · $1.00 / 1k | Trial |
| SMTP.com | Pay as you go | ~$55.00 · $1.10 / 1k | Trial |
| Emailit | Pay as you go | ~$60.00 · $1.20 / 1k | Free tier |
| Mailjet | Pay as you go | ~$60.00 · $1.20 / 1k | 200 emails/day free plan |
| SocketLabs | Pay as you go | ~$60.00 · $1.20 / 1k | Trial credits |
| useSend | Pay as you go | ~$60.00 · $1.20 / 1k | Self-host free |
| Postmark | Pay as you go | ~$62.50 · $1.25 / 1k | 100 emails/mo trial-style |
| Brevo | Pay as you go | ~$70.00 · $1.40 / 1k | 300 emails/day free |
| Mailgun | Pay as you go | ~$70.00 · $1.40 / 1k | Trial credits |
| Mailgun EU | Pay as you go | ~$70.00 · $1.40 / 1k | Trial |
| Mailtrap Email API | Pay as you go | ~$70.00 · $1.40 / 1k | Sandbox free; sending has free tier |
| Brevo SMS+Email | Pay as you go | ~$75.00 · $1.50 / 1k | Shared Brevo free |
| GreenArrow | Pay as you go | ~$75.00 · $1.50 / 1k | Demo |
| MailerSend | Pay as you go | ~$75.00 · $1.50 / 1k | 3,000 emails/mo free |
| SparkPost | Pay as you go | ~$75.00 · $1.50 / 1k | Trial / starter |
| Mailpace | Pay as you go | ~$80.00 · $1.60 / 1k | Trial |
| Resend | Pay as you go | ~$80.00 · $1.60 / 1k | 3,000 emails/mo free |
| SendGrid | Pay as you go | ~$80.00 · $1.60 / 1k | 100 emails/day free forever |
| Mailchimp Transactional | Pay as you go | ~$90.00 · $1.80 / 1k | Tied to Mailchimp plans |
| Loops | Pay as you go | ~$100 · $2.00 / 1k | 1,000 emails/mo free |
| OneSignal Email | Pay as you go | ~$100 · $2.00 / 1k | Free messaging tier (limits apply) |
| Plunk | Pay as you go | ~$100 · $2.00 / 1k | Free tier |
| Campaign Monitor | Pay as you go | ~$125 · $2.50 / 1k | Trial |
| Infobip | Pay as you go | ~$125 · $2.50 / 1k | Trial |
| Sinch Email | Pay as you go | ~$125 · $2.50 / 1k | Trial |
| Buttondown | Pay as you go | ~$175 · $3.50 / 1k | Free tier |
| Moosend | Pay as you go | ~$175 · $3.50 / 1k | Trial |
| Vonage Messages | Pay as you go | ~$175 · $3.50 / 1k | Trial credit |
| GetResponse | Pay as you go | ~$200 · $4.00 / 1k | Trial |
| Mailchimp | Pay as you go | ~$200 · $4.00 / 1k | Free plan (tight limits) |
| Omnisend | Pay as you go | ~$200 · $4.00 / 1k | Free plan |
| ActiveCampaign | Pay as you go | ~$225 · $4.50 / 1k | Trial |
| Kit (ConvertKit) | Pay as you go | ~$225 · $4.50 / 1k | Free up to subscriber limit |
| Courier | Pay as you go | ~$250 · $5.00 / 1k | Free developer tier |
| Drip | Pay as you go | ~$250 · $5.00 / 1k | Trial |
| Klaviyo | Pay as you go | ~$250 · $5.00 / 1k | Free plan up to profile limits |
| Knock | Pay as you go | ~$250 · $5.00 / 1k | Free developer tier |
| Customer.io | Pay as you go | ~$300 · $6.00 / 1k | Trial |
| HubSpot Transactional | Pay as you go | ~$400 · $8.00 / 1k | Marketing Hub free has limits |
| Adobe Campaign | Pay as you go | ~$750 · $15.00 / 1k | Sales-led |
| Oracle Eloqua | Pay as you go | ~$750 · $15.00 / 1k | Sales-led |
| Salesforce Marketing Cloud | Pay as you go | ~$750 · $15.00 / 1k | Sales-led |
17 — Feature comparison · Oct 2026
28 email APIs, on the jobs developers actually need
Filter by capability, or expand a card. MailShrine stays highlighted. Marks cover PAYG credits, never-expire packs, Sandbox, REST, SMTP, SDKs, CLI, signed webhooks, Domain Auth, templates, suite login, NGN billing, and Stella.
28 of 28 companies
Feature matrix
| Company | PAYG | No expiry | Sandbox | REST | SMTP | SDKs | CLI | Webhooks | Domains | Templates | Suite | NGN | AI |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| MailShrineUs | |||||||||||||
| ZeptoMail | |||||||||||||
| Elastic Email | |||||||||||||
| Netcore Email API | |||||||||||||
| Postmark | |||||||||||||
| SendGrid | |||||||||||||
| Unisender Go | |||||||||||||
| Brevo | |||||||||||||
| MailerSend | |||||||||||||
| Mailgun | |||||||||||||
| Mailjet | |||||||||||||
| Mailtrap | |||||||||||||
| Plunk | |||||||||||||
| Resend | |||||||||||||
| SocketLabs | |||||||||||||
| Infobip | |||||||||||||
| SparkPost | |||||||||||||
| Loops | |||||||||||||
| Mailchimp Transactional | |||||||||||||
| Scaleway TEM | |||||||||||||
| SMTP2GO | |||||||||||||
| Klaviyo | |||||||||||||
| OneSignal | |||||||||||||
| ActiveCampaign | |||||||||||||
| Courier | |||||||||||||
| Customer.io | |||||||||||||
| HubSpot | |||||||||||||
| Knock |
Developer API Guides
Learn the path, not the jargon.
Developer API Tools
Playground, webhooks, DNS, SMTP.
API Playground
Try send and inspect responses from the browser with your suite session.
Webhook tester
Understand payload shapes for opens, clicks, bounces, and complaints.
DNS checker
Validate SPF, DKIM, and DMARC records for your sending domain.
SMTP connection doctor
Confirm relay host, TLS, and credentials before production traffic.
Ready to send from your product?
Sign in with your MailShrine account to open the Developer API dashboard — same login as the rest of the suite.