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DeliverabilityUpdated · 7 min read

Email Analytics for Developers: Opens, Clicks, Bounces

A developer's guide to email analytics: which events matter (delivered, bounce, complaint, open, click), why opens are unreliable, and how to wire up webhooks to act on the data.

MT
Mailbase Team
email analytics for developers
On this page · 8 sections

Overview

Email analytics is the data trail behind every send — and for developers it's mostly a question of which events to trust and what to do with them. The events you get from a provider (delivered, bounced, complained, opened, clicked, unsubscribed) aren't equally reliable, so the skill is weighting them correctly and wiring the important ones into your system instead of just staring at a dashboard.

The events, and which to trust

Trust these: delivered/bounced (did it reach the server), complained (someone hit spam — act on every one), clicked (real intent), and unsubscribed. Treat opens with heavy skepticism — open tracking fires a pixel, and Apple Mail Privacy Protection and similar features pre-load that pixel, inflating opens with events no human made (see average email open rate). Use opens as a rough, directional signal at best.

For decisions, lean on clicks, conversions, replies, and complaint/bounce rates. A bounce or complaint event is far more actionable than an open: it should trigger suppression automatically, not just a chart.

  • Reliable: delivered, bounced, complained, clicked, unsubscribed
  • Unreliable: opens (pixel pre-fetching inflates them)
  • Decide on clicks, conversions, replies, complaint/bounce rates
  • Complaints and hard bounces should trigger action, not just a metric

Wire events into your system with webhooks

The developer move is to consume provider webhooks (or Mailbase's outgoing webhooks) so events drive behavior: auto-suppress on hard bounce and complaint, update user state on delivery failure, trigger flows on click. Verify webhook signatures, make handlers idempotent (events can be re-delivered), and log with redacted metadata so you can debug without leaking PII.

Match the provider message ID to your recipient so per-recipient attribution is clean. Mailbase attributes provider message IDs per recipient, filters machine opens/clicks where possible, and stores redacted webhook debug logs with replay — so the numbers you act on separate real engagement from scanners. See Mailbase deliverability controls.

  • Consume webhooks; auto-suppress on bounce/complaint
  • Verify signatures; make handlers idempotent
  • Map provider message IDs per recipient
  • Filter machine opens/clicks; log with redacted PII

Common mistakes

  • Skipping SPF, DKIM, and DMARC, or assuming they're a one-time setup.
  • Sending real volume from a brand-new, un-warmed domain.
  • Reusing a stale list without re-verifying, so bounces spike.
  • Ignoring complaint rate until a single bad campaign sinks the domain.

Sources and further reading

Official docs for current setup details, pricing, and API behavior — verify specifics there, since they change.

Amazon SES docsSupabase custom SMTP docs

Related guides

More on email analytics for developers and the surrounding deliverability workflow:

free domain checkSPF, DKIM, and DMARCdeliverability and honest warm-upbounce managementsuppression listsunsubscribe best practicessender domain docs
Questions

About this page.

Which email metrics actually matter?
Delivered/bounce, complaint, click, conversion, and unsubscribe rates are the actionable ones. Opens are inflated by privacy proxies pre-loading the tracking pixel, so treat them as rough and directional. For real engagement and decisions, lean on clicks, conversions, and replies.
Are email open rates accurate?
Not reliably. Open tracking fires an invisible pixel, and Apple Mail Privacy Protection and similar features pre-load it, registering opens no human made. Use open rate as a loose directional signal, not a precise KPI, and judge engagement by clicks and replies.
How do I act on email events as a developer?
Consume your provider's webhooks (or Mailbase's outgoing webhooks): auto-suppress on hard bounce and complaint, trigger flows on click, and update user state on failure. Verify webhook signatures, make handlers idempotent since events can be re-delivered, and log with PII redacted.
How do I attribute email events to the right user?
Map the provider's per-message ID back to your recipient when you send, so each delivery, bounce, click, or complaint ties to a specific user. Sending per recipient (as Mailbase does) keeps that attribution clean rather than guessing from a shared campaign ID.