Open and click tracking

Tracking is off unless you turn it on. It only applies to emails with an HTML body.

Turn it onCopy Anchor Link

Each project has two defaults, Open tracking and Click tracking, under Settings → Tracking in the dashboard (trackOpens and trackClicks on the project). Any send can override them:

await flaresend.emails.send({
  from: 'Acme <hello@acme.com>',
  to: 'ada@example.com',
  subject: 'New features in October',
  html: '<p>Read about them <a href="https://acme.com/blog/october">on our blog</a>.</p>',
  trackOpens: true,
  trackClicks: true,
});

The email record shows what was applied in trackOpens and trackClicks. Both are false for a text-only email, whatever you asked for.

How opens are trackedCopy Anchor Link

Just before sending, Flaresend adds a 1×1 transparent image to the HTML, before </body> (or at the end if there is no </body>). Its URL is <PUBLIC_BASE_URL>/t/o/<token>, where the token is an HMAC of the email ID.

When a mail client loads the image:

• The first load sets openedAt on the email and adds an email.opened event with the User-Agent in its data. That event goes to webhooks subscribed to email.opened.
• Later loads return the image and record nothing. An email has at most one email.opened event.

How clicks are trackedCopy Anchor Link

Flaresend rewrites the href of every <a> tag to <PUBLIC_BASE_URL>/t/c/<token>, and stores the original URL. A click records the event and answers with a 302 redirect to the original URL.

Links that are not rewritten:

• Anything that isn't http:// or https://: mailto:, tel:, #anchors and relative links.
• URLs that still contain {{, such as an unrendered template variable.
• Links that already point at the mailer itself (tracking and unsubscribe links).

Every click is recorded, not just the first. Each one adds an email.clicked event with the url and User-Agent, increases that link's click count, and sets firstClickedAt on the email the first time. A token that doesn't exist returns 404; the click route never redirects to a URL it didn't store.

What doesn't changeCopy Anchor Link

• The original HTML you sent is stored untouched. The tracked copy is stored next to it, and Retrieve email content returns both (html and trackedHtml).
• If the send is retried, the same tracked copy is reused, so links aren't rewritten twice.

Accuracy and privacyCopy Anchor Link

• Opens are an estimate. Many clients block remote images, so real opens are missed. Others (for example Apple Mail Privacy Protection and some security scanners) load images automatically, so an "open" can happen without a person reading the email.
• Clicks can come from scanners too. Link-checking software in some mail systems follows links before the recipient does.
• Tracking adds your mailer's domain to every link, which some spam filters look at. For password resets, sign-in links and other security email, leave click tracking off.
• Tracking records when and from which user agent an email was opened or clicked. Tell your users if your privacy policy requires it.

Reading the numbersCopy Anchor Link

• Per email: openedAt, firstClickedAt and the email.opened / email.clicked events on Retrieve an email.
• Per project: opened and clicked in Analytics.
• Live: subscribe a webhook to email.opened and email.clicked.