Email API10 min

Send email from your app

Receipts, sign-in codes and notifications from your own software, on your own domain.

1. 1

   Mark your domain for transactional email

   In Settings → Domains, verify your domain if you have not, then mark it for transactional email.

2. 2

   Create a key

   Open Email API → API keys and create a sending key. It is shown once — keep it in an environment variable on your server, never in a browser.

3. 3

   Send your first email

   One request sends one message:

   curl -X POST https://emailapi.mercestack.com/v1/email \
     -H "Authorization: Bearer msk_live_…" \
     -H "Content-Type: application/json" \
     -d '{
       "from": "Acme <[email protected]>",
       "to": "[email protected]",
       "subject": "Your receipt",
       "html": "<p>Thanks for your order.</p>"
     }'

4. 4

   Watch it arrive

   Email API → Emails shows every message and what happened after it left: delivered, bounced or marked as spam. Add a webhook to hear about it in your own app.