Why you must fix email deliverability now

Have you noticed fewer marketing emails getting through—or ones you want landing in spam? You’re not imagining it. Google, Apple, and Microsoft now use AI to judge whether to place, promote, or suppress your mail. If you don’t fix email deliverability, those systems quietly erode your sender reputation while you tweak subject lines.

Email still drives serious return—42% of B2B acquisition and ~£35 per £1 spent—but only if your messages actually arrive. If your team isn’t acting to fix email deliverability, you’re burning money and brand trust with every send.

The invisible judge behind every send

Inbox AI doesn’t “read” your prose. It watches behaviour: opens, clicks, replies, deletions, and spam reports. It also looks at patterns across the list. A run of ignored emails tells the system your next one will be ignored too—so it buries it. That spiral compounds until you’re reaching a fraction of your list. To fix email deliverability, you must reverse those signals.

The death spiral (and the turnaround)

A client arrived with 6,000 subscribers and 8% opens. The content wasn’t the issue—the list was. Thousands were “inbox zombies” (no opens for months). Every send to them trained Outlook and Gmail to down-rank everything. We cut 3,000 contacts. Open rate jumped to 28% immediately. Fewer contacts. More engagement. That’s how you fix email deliverability in practice.

Hard bounces will wreck you

Sending to invalid addresses is a fast way to tank reputation. Every hard bounce is a black mark. Before your next campaign, verify your list (ZeroBounce, NeverBounce, Instantly.ai). Remove dead addresses. A smaller, verified list outperforms a big, dirty one—and it helps fix email deliverability fast.

What to do right now to fix email deliverability

1) Audit the list this week

Pull everyone who hasn’t opened in 90 days. Send a plain, human re-permission email: “Should I keep sending these?” Make staying or leaving one click. Remove non-responders. Your total goes down; your reputation goes up. That’s step one to fix email deliverability.

2) Verify every address before the next send

Use a verifier to catch typos, dead domains, and role accounts. Remove hard bounces and high-risk records. This single move can materially fix email deliverability within days.

3) Segment like revenue depends on it

Stop blasting everyone. Segment by behaviour (opens last 5, clicks last 3, replied recently, 30/60/90-day inactive). Send different messages to new subscribers vs six-month fans. Blended irrelevance kills averages; relevance helps fix email deliverability.

4) Make emails look less like marketing

Heavy HTML, banners, multiple buttons = “promo” to filters. Use simple, mostly text emails that feel like a person wrote them. Short paragraphs, white space, one clear CTA. This alone helps fix email deliverability because it earns better engagement signals.

5) Ask questions that earn replies

Nothing boosts reputation like genuine replies. End with one specific question people can answer:

• “What’s the biggest block to shipping your newsletter weekly?”

• “Pick one: template, case study, or teardown—what’s most useful next?” Even a handful of replies per send helps fix email deliverability across your domain.

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6) Stay consistent (cadence > bursts)

Erratic bursts trigger scrutiny. Choose a schedule you can keep and stick to it. During launches, stage messages so the overall rhythm stays steady. Consistency is how you fix email deliverability long-term.

Your quick checklist to fix email deliverability (internal, not for subscribers)

• Clean: remove 90-day inactives who don’t re-opt.

• Verify: run the list before each big send.

• Segment: message by behaviour and lifecycle.

• Simplify: plain layouts, one clear CTA.

• Invite replies: one specific question each send.

• Cadence: predictable schedule, not spikes.

• Monitor: track inbox placement, spam complaint rate, hard bounces, and engaged opens (not vanity opens from privacy proxies).

  
  

The bottom line

Email hasn’t died—it evolved. Filters reward relevance and punish laziness. If you fix email deliverability now, you’ll outpace competitors who are still blasting zombies and training the AI to ignore them.

Your goal isn’t a bigger list. It’s a more engaged one.

Treat your sender reputation like a credit score. Guard it. Grow it. And if your team isn’t already moving on this, show them this article—and make them fix email deliverability before the damage compounds.

Need help getting out of the spam folder and turning email into a reliable revenue channel? Let’s talk: www.reasonwhy.co.uk