Transactional email

You can send real-time transactional emails using our communications functionality in the API.

Features include:

  • The content of the transactional email can be HTML and/or plain text based
  • Use triggered templates to send transactional email
  • Data merge using data passed in the API call
  • Bulk methods for high volume sending
  • Attachment support
  • Feedback via webhooks

Ways of sending transactional email

We offer a range of ways to send transactional emails from built in functions in our integrations and a variety of API and protocol based methods, such as:

API based

Use our Transactional Email API to send transactional email individually or in bulk using explicit content or triggered templates with data merge. Check out the following methods to learn more, Transactional Email API

SMTP based

Use SMTP to send transaction email using your favourite email tools and or libraries; the full process is explained in our guide here


Send limits

Calls to the Transactional Email API do not count towards your hourly API call limits, however by default you are limited to 50,000 per UTC calendar day. Please talk to you account manager if you need more capacity per day.

Receiving status updates

If you wish to receive status updates on your transactional email sends you can do via our Webhooks is near real-time. You can optionally subscribe to the following event types:

  • message.sent - Sent whenever you successfully send a transactional email
  • message.delivered - Sent when we know a message is delivered, and is inferred from when the email is read
  • - Sent when a message is read / opened
  • message.failed - Sent if there is a terminal problem processing your email send
  • complaint.received - Sent if a recipient of your transactional email complains about the email. We recommend reacting to these and ensuring you do not send further emails to this recipient.
  • - Sent whenever a recipient clicks on a tracked link within your emails. Use a triggered campaign based Transactional Email to add tracked links to your emails.

Making events easier to correlate and process

When sending your transactional email messages via the Transactional Email API you can optionally specify metadata, and/or tags can be added via the API or using campaign tags associated with a triggered campaign template. We include this metadata and any tags in the webhook events related to the transactional email. By including your own keys and data you can make it far easier to process the received webhook events by avoiding the need to perform a lookup prior to processing potentially.

Template based transactional email

Users of Dotdigital can create a transactional email template as a triggered campaign in EasyEditor.

It then needs to be sent either via SMTP, or via our API; see:

The numeric campaign ID is used in the call to identify the triggered campaign to send as a transactional email.

Personalisation can also be used in the transactional email template by adding placeholders such as @[email protected] in the triggered campaign in Dotdigital.

The personalisation values are then supplied either in the SMTP headers or in the API call's parameters. These take the form of key-value pairs.

Unsupported EasyEditor building blocks and links

Transactional email templates don't support the following EasyEditor building blocks and link types:

  • 'RSS feed'
  • 'Sharing'
  • 'Social links'
  • 'Dynamic content'
  • 'External dynamic content'
  • 'Advanced personalisation' blocks
  • 'Forward to a friend' link
  • 'Unsubscribe' link (but you will need to include one in order to save your template in EasyEditor; read 'About unsubscribe links' in our 'Creating and designing a transactional email template' support article)
  • 'View in browser' link
  • 'Double opt-in' link


A note on HTML compatibility for personalisation content

When making use of transactional email personalisation, the type of personalised content needs to be compatible with the HTML element it's being put into in EasyEditor. For example, if your code contains a personalised table, it will need to go into a table element in the template, not a paragraph.

Check with your campaign designers to ensure that their campaign's elements are suitable for the personalisation content being used.

Monitoring transactional email

You can monitor the usage of the transactional email system via the Dotdigital portal by opening the Transactional Email area from the left-hand menu bar. You can:

  • Analyze usage and deliverability
  • Download messages
  • View complaints
  • Configure usable from addresses, and request new ones
  • Configure link tracking
  • Setup SMTP credentials
The transactional email dashboardThe transactional email dashboard

The transactional email dashboard

Avoiding deliverability issues

It is important that only transactional style emails and not marketing are sent via the Transactional Email API, and the recipient is expecting to receive the email, as opt out checks will not be applied! We recommend if you receive a complaint.received webhook event that you stop sending email to this recipient immediately, as the complaints damage the reputation and therefore deliverability of emails of the domain and IP address the email was sent from.

You can also view received complaints with regards to transactional email in the Dotdigital portal by opening the Transactional Email area from the left-hand menu bar, and selecting Settings > Complaints from the top menu:

Viewing your transactional email complaintsViewing your transactional email complaints

Viewing your transactional email complaints


Do not ignore complaints

If you are receiving complaints please ensure you stop emailing these recipients, and if you receive many complaints please review your emails contents to see if it:

  • Is transactional in nature i.e. informative, an update on a service or purchase the recipient has used/done
  • Is expected, you informed the recipient that you would be sending the emails

If too many complaints are received then we may withdraw your use of the Transactional Email API, and complaints are continually monitored by our deliverability team!


Learn more about transactional email

For an overview on transactional email, check out our Help centre article .

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