From Spam to Inbox: Your Path to Perfect Email Deliverability

Picture this:

There’s a hot new club in town. You’re dressed to impress. But when you get to the door, the bouncer gives you the once-over and mutters, “Name’s not down, you’re not coming in.”

That bouncer? It’s your inbox provider. And that club? It’s your subscriber’s inbox.

Deliverability isn’t automatic. You have to earn it.

…And here’s the thing, most people don’t even realise they’ve got an issue—until open rates nosedive and clicks vanish.

Why? Because tools like Mailchimp don’t actually tell you whether your emails made it to the inbox. You see opens and clicks, sure—but not the real gatekeeper stats.

And that’s risky.

Because if your emails are bouncing, buried, or quietly shunted to spam, your campaign’s already sunk before anyone’s even had the chance to read it.

Here’s the truth: Inbox providers are getting stricter. If you’re not playing by their rules, you’re not getting through the door.

So, what do you do? 

You follow these 5 rules like your email reputation depends on it (because let’s be honest, it does):

So how do I improve deliverability?

If you’re dead serious about conquering email deliverability hurdles and outsmarting the bouncer, following these 5 simple steps is an absolute must.

1. Verification & Authentication
2. List Quality
3. Reputation
4. Content and Format
5. Testing

1. Are you really who you say you are? – Verification & Authentication

In order for Mailchimp to send emails that look like they’re coming from your domain, they need to make sure it’s legit. It starts with verification—clicking a confirmation email—but the real juice is in domain authentication.

Authentication is like a passport for your emails. It tells inbox providers that your message is trustworthy, significantly boosting deliverability.

To do this, you’ll need to access your domain host and update your DNS records with SPF, DKIM, and DMARC. If that sounds technical—it is, but it’s essential. And it’s worth doing properly.

Avoid sending from free email addresses like @gmail.com or @yahoo.com—they can’t be authenticated and just scream “amateur” to inbox providers.

2. How good is your list? – List Quality

List quality is often the silent killer of deliverability. If your list is full of outdated, disengaged, or invalid email addresses, inbox providers will flag you as a spam risk.

Use a double opt-in process to ensure new subscribers really want to hear from you. Clean your list regularly using tools like BriteVerify or Kickbox to remove inactive or invalid addresses.

Think of your list like a garden—it needs regular pruning and nurturing to thrive.

Inactive subscribers hurt your metrics. Remove them. Focus your energy on people who are actually opening and clicking.

3. What have you done in the past? – Reputation

Inbox providers are digital detectives. They track every interaction your emails receive:

• Opens
• Clicks
• Replies
• Forwards
• And yes, even deletions and spam complaints

These signals build your sender reputation. A good one means more inbox placement. A bad one? Straight to spam.

Want to build reputation fast? Nail your first email:

• Send it immediately after sign-up
• Make sure it’s relevant
• Ask to be added to their address book
• Encourage clicks
• Even better? Ask for a reply. That’s a massive trust signal to inbox providers.

4. What’s in the email? – Content & Format

The content of your email matters. A lot.

Avoid spammy words (“earn £££ fast”, “act now”) and poor formatting. Don’t go all-image with no text, and make sure your HTML is clean.

Keep your subject lines honest and relevant. Overuse of CAPS LOCK or excessive punctuation (!!!) are red flags to spam filters.

And don’t forget responsiveness—your email needs to look sharp on mobile too.

Include a clear CTA. Make it easy to understand what you want the reader to do next. Less confusion = more clicks.

5. Did it work? – Testing

Testing is your safety net.

Before hitting send, check:

• All links work
• Images load correctly
• Email renders well on different devices
• Personalisation fields are working
• It doesn’t land in spam (use tools like Mail Tester to find out)

Test subject lines, layouts, and send times to see what resonates. Small improvements here can lead to big wins.

Pro Tip: Be a DORC

DORC stands for Deliverability, Openability, Readability, and Clickability.

It’s our four-part formula for email success—and deliverability is just the beginning.

If you improve each of these areas by just 5%, the compound effect could boost your click rates by 50%. That’s not theoretical—that’s maths.

Deliverability: Your email makes it to the inbox.
Openability: Your subject line and sender name entice a click.
Readability: Your content is easy to digest.
Clickability: You drive the action you want.

 Read more about the DORC Methology

Final Thought:

Deliverability isn’t the sexy part of email marketing. But without it? None of the other stuff matters.

Your design. Your copy. Your CTA. All wasted if your email never even lands in the inbox.

So next time you send, ask yourself:

Have I DORC-ed this?

Because when you do—it shows. In your stats. In your engagement. In your results.

And that’s when email marketing actually works.