Email Open Rates Are Crashing

If you run email campaigns for a Sydney business, you have probably watched the open-rate column on your dashboard slowly turn the wrong colour over the past six months. Campaigns that consistently hit 30-40% opens in 2024 are sitting at 12-18% in 2026 — on the same lists, the same subject lines, the same days of the week. The list did not get worse. The inbox did.

Four specific changes converged in the first quarter of 2026 to collapse open rates across the board, and each one has its own fix. The good news: email is not dying. It is still, by a wide margin, the highest-ROI channel for most Australian SMBs. But the way you measure success and the way you structure campaigns both have to change.

Reason 1: Apple Mail Privacy Made Open Rates Lie

Apple's Mail Privacy Protection, rolled out gradually across iOS and macOS, now pre-fetches all email images regardless of whether the user actually opened the email. This means every email sent to an Apple Mail user is counted as "opened" by your ESP — even if the user never saw it.

On the surface this inflates open rates. In practice, it has destroyed the signal entirely. Email service providers that used to use opens to decide which emails were engaging now have unreliable data, which has cascaded into other problems: bad segmentation, broken re-engagement triggers, and inflated win-back lists that contain users who have not actually opened anything in two years.

Reason 2: AI-Summarised Inboxes

Gmail, Apple Mail, Outlook, and Superhuman have all rolled out AI-powered inbox summaries that compress promotional emails into a single line of text — sometimes a single phrase. Users now scan five summarised emails in the time they used to spend opening one.

This sounds bad, and in some ways it is. But it also restructures what makes an email "work". Subject lines that used to win on curiosity gaps ("you won't believe what happened next") now lose, because they summarise badly. Subject lines that lead with the actual offer or news win, because they survive the summarisation step intact.

Reason 3: Sender Authentication Got Strict

In late 2024, Google and Yahoo started enforcing strict sender authentication requirements: SPF, DKIM, and DMARC properly configured, with valid alignment, or your email goes straight to spam. Through 2025 and into 2026, those requirements have tightened further. Microsoft's Exchange Online has been particularly aggressive.

For Sydney businesses sending from custom domains (yourname@yourbusiness.com.au), a misconfigured DKIM record or a too-loose DMARC policy is now a guaranteed deliverability disaster. Many businesses with these problems do not even realise it — their newsletter never reaches half their audience, and they assume open rates dropped because of disengagement.

Reason 4: Engagement Filters Got Smarter

Gmail's inbox filters now consider not just spam scores, but engagement history. If a user has not opened or clicked an email from your domain in 90+ days, future emails from you are increasingly likely to land in Promotions or Spam — regardless of how well-authenticated they are.

The implication is that list size has stopped being a useful metric. A list of 50,000 people that never engage is actively hurting your deliverability for the 5,000 who do. Larger is not better. Engaged is better.

The Five Practical Fixes

Here is the playbook for any Sydney business with a crashing open rate.

1. Stop measuring opens. Start measuring clicks and replies. Build all KPIs around CTR. Build retention triggers around clicks, not opens. Build win-back campaigns around 90 days without a click, not 90 days without an open. The new metric reflects reality; the old one is inflated noise.

2. Run a deliverability audit. Plug your domain into a deliverability tool. Confirm SPF, DKIM, and DMARC are all aligned. If you do not understand what those acronyms mean, that is fine — but make sure someone in your stack does. A misconfigured DKIM costs more revenue than any subject-line A/B test can recover.

3. Sunset unengaged subscribers. Yes, ruthlessly. Anyone who has not clicked an email in 6 months goes through a single re-engagement attempt, and if they do not respond, they are removed. Your sender reputation improves. Your real engagement rate becomes visible. Your subsequent emails to engaged users hit the inbox more reliably.

4. Rewrite subject lines for summarisation. Lead with the news. "20% off this weekend only" beats "you'll never guess what we did". The summarisation pass kills curiosity gaps and rewards direct value statements.

5. Invest in SMS. Email is not dying, but it is no longer the only real direct-to-customer channel. SMS open rates remain in the 90s. For frequent-purchase or local Sydney businesses, an SMS list of 2,000 people often outperforms an email list of 20,000.

The Bottom Line

Email is not broken. The way most Sydney businesses measure email is broken. The Apple privacy change, the AI inbox summaries, the stricter authentication, and the engagement-aware filters have collectively redefined what success looks like — and the businesses that update their measurement, clean their lists, and respect deliverability fundamentals will keep winning the inbox.

The ones who keep watching opens go down without changing anything will keep losing — and they will keep blaming the channel rather than the practice. Email is still the highest-ROI marketing channel for most Australian SMBs. It just rewards a different playbook in 2026.