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What Is Transactional Email?

Transactional email is an automated message sent to a single recipient in response to a specific action, such as a password reset, order confirmation, or account verification. Unlike marketing email sent in bulk, transactional email is triggered by user behavior and typically achieves open rates above 80%.

Common examples include password reset emails, order receipts, shipping notifications, account verification links, and two-factor authentication codes. RelayPost delivers transactional email through a REST API and SMTP relay with automatic DKIM signing and real-time delivery tracking.

  • Password reset links
  • Order confirmation receipts
  • Shipping and delivery notifications
  • Account verification emails
  • Two-factor authentication codes
  • Invoice and payment receipts
  • Welcome emails after signup
  • Subscription renewal notices
AspectTransactional EmailMarketing Email
TriggerUser action (purchase, signup)Business decision (campaign)
RecipientsSingle individualList or segment
ContentExpected, action-specificPromotional, informational
Open rate80–90%15–25%
UnsubscribeNot required (service messages)Required by law (CAN-SPAM)
ExamplesPassword reset, order receiptNewsletter, product announcement
Sending methodAPI trigger from app codeCampaign builder or scheduler
  1. Choose an email delivery service with a REST API or SMTP relay
  2. Verify your sending domain with SPF and DKIM records
  3. Generate an API key from your provider’s dashboard
  4. Build the email payload with sender, recipient, subject, and HTML body
  5. Call the send endpoint from your application code when the triggering event occurs
  6. Set up webhooks to track delivery, bounces, and opens in real time

RelayPost provides both a REST API and an SMTP relay for sending transactional email.

Transactional emails include password resets, order confirmations, shipping notifications, account verification links, two-factor authentication codes, invoice receipts, and welcome emails triggered by user signup.

What is the difference between transactional and marketing email?

Section titled “What is the difference between transactional and marketing email?”

Transactional email is triggered by a user action (like a purchase or password reset) and sent to one recipient. Marketing email is sent in bulk to a list or segment as part of a campaign. Transactional email typically has open rates above 80%, while marketing email averages 15–25%.

Section titled “Do transactional emails need an unsubscribe link?”

No. Transactional emails are service messages triggered by user actions and are exempt from CAN-SPAM unsubscribe requirements. However, if a transactional email contains promotional content, it may be classified as marketing email and require an unsubscribe link.

What is a good open rate for transactional email?

Section titled “What is a good open rate for transactional email?”

A good open rate for transactional email is 80–90%. Because these emails are expected by the recipient (password resets, order confirmations), they consistently achieve much higher engagement than marketing email.