stmpr Knowledge base

Transactional email and SMS

Send reward notifications using Twilio, SendGrid, Mailgun, Postmark, or Mandrill.

Connect Twilio, SendGrid, Mailgun, Postmark, or Mandrill directly with your own provider account, verify the credentials, and send a test message from stmpr.

These connections are delivery transports for reward-ready notifications, redemption confirmations, and operational messages. Custom multi-step workflows can still use Zapier, Make, or stmpr webhooks.

The provider needs a verified sender and correct domain or phone configuration. Decide whether each message is transactional or marketing before enabling it.

Make · stmpr → Twilio
SendGrid / Postmark · Template
Workflow
  1. 1stmpr reward or redemption event
  2. 2Permission and template selection
  3. 3Twilio SMS or transactional email provider

Step by step

  1. Verify a sender in the provider first: a purchased or verified phone number in Twilio, or an authenticated sender email and domain for the email providers.
  2. Open Integrations, connect the provider with the credentials listed below, and enter the verified sender.
  3. Send a test message from the integration card to your own address or phone and inspect the provider delivery log.
  4. For automated sending, create an stmpr webhook only for events that should trigger the message and build the flow in Zapier, Make, or your backend.
  5. Map safe template values such as customer name, reward, and store name.
  6. Deduplicate by stmpr event ID so webhook retries cannot send the message twice.

Where to find each credential

  • Twilio (SMS): the Account SID (starts with AC) and Auth Token on the Twilio Console home page; the sender must be a Twilio phone number you own.
  • SendGrid: Settings → API Keys → Create API Key with at least Mail Send permission; verify the sender under Settings → Sender Authentication.
  • Mailgun: the private API key under API Security → Mailgun API keys, plus your sending domain from Send → Domains; pick the US or EU region matching where the domain was created.
  • Postmark: the Server API token under your server's API Tokens tab; the sender must be a confirmed Sender Signature.
  • Mandrill (Mailchimp Transactional): the API key under Settings → API keys in Mailchimp Transactional.
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