Click Send… Then What?
Understanding How Email Really Works
Sending an email might feel as simple as pressing a button, but behind the scenes, it’s more like sending a letter across a border with multiple customs checks. Remember COVID times?
First, your message leaves your email platform (like MailerLite, Outlook, or Gmail)—this is the digital version of dropping a letter into a mailbox.
Then it’s scanned by invisible border agents who ask:
- “Who sent this?”
- “Are they legit?”
- “Can I trust this envelope?”
- “Is this spam, or something the recipient is expecting?”
These invisible border agents are very fussy and will ask your email to provide the necessary papers before it is allowed to cross the border. What papers?
- SPF – like checking your return address
- DKIM – a digital signature to prove it hasn’t been tampered with
- DMARC – your written instructions for what to do if those checks fail
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Let’s not get too hung up on the paperwork for now. All will be revealed! And no, you won’t need an IT degree to understand it all.
Before we dig in, here are two of my favourite tools when it comes to understanding and troubleshooting email deliverability.
Visual Learner? Check This Out!
Want to see how email authentication works behind the scenes?
DMARC Tester gives you a visual, step-by-step demo of what happens when you hit “Send.”
It’s a fantastic way to get your head around SPF, DKIM, and DMARC—without the jargon overload.
📌 Bookmark it now, and take a closer look when you’ve got a few spare minutes.
For now, though, lets stick to the basics.
Is Your Email Getting Through?
If you’re wondering whether your emails are actually landing in inboxes or quietly slipping into spam, this free tool is your new best friend.
Mail Tester gives your email a score based on key deliverability factors like SPF, DKIM, and blacklists. Simply send a test email to the address provided, then click the button to view your score.
It’s quick, easy, and surprisingly eye-opening.
Give it a go and check your score
📬 What Happens When You Hit Send?
Sending an email might feel instant, but under the hood, there’s a mini relay race happening.
Here’s a simplified, step-by-step version of what really goes on:
- Your email platform (like Gmail, Outlook, or MailerLite) prepares the message and hands it off to your email server. Think of this as dropping your letter into the mailbox.
- Your email server then looks up the recipient’s mail server, much like checking the address and selecting the most suitable courier. “Where does this letter need to go?”
- Before your message is delivered, the recipient’s mail server checks a few things to see if you’re trustworthy:
- Is this domain allowed to send emails from this address? (That’s SPF)
- Has this message been altered along the way? (That’s DKIM)
- What should we do if something doesn’t check out? (That’s DMARC)
- If your email passes all those checks, the recipient’s server says “Come on in,” and your message lands in the inbox (or sometimes, the promotions tab or spam folder—more on that later).
- If something looks suspicious, the message may be flagged, rerouted, delayed, or blocked entirely.
Don’t stress about what SPF, DKIM, and DMARC actually are—or how to set them up.
Just know this: you need them. They’re like passports, ID, and customs forms for your emails. Without them, your message might never make it to the other side.
Why Email Deliverability Really Matters
You could write the perfect email with a clever subject line, a beautiful layout, and a compelling message…
But if it doesn’t land in someone’s inbox?
📉 No one reads it
📉 No one clicks
📉 No one buys
📉 You just wasted time (and maybe money too)
That’s the reality of poor deliverability. Email deliverability isn’t just a “tech issue.” It’s a business issue.
It affects;
- Client communications – Missed invoices, appointment confirmations, or onboarding emails.
- Sales & marketing – Your offers can’t convert if they never arrive.
- Reputation – A dodgy sender reputation can mean future emails get blocked too.
And here’s the kicker:
You often don’t know there’s a problem until someone tells you they didn’t get the email. That’s why it’s so important to set up your “email trust signals” properly (we’ll get to those next).
Think of email deliverability as making sure your mailman knows the right route, carries ID, and doesn’t look suspicious when dropping letters at someone’s door. Because if the inbox gatekeepers don’t trust you, they won’t let you in.
Email Trust Signals: Proving You’re Not a Spammer
When your email lands at the border (aka your recipient’s mail server), the first thing it needs to do is prove it’s not dodgy. This is where trust signals come into play.
Think of them like the uniform, ID badge, and company letterhead that show you’re legit.
Here are the big three:
✅ SPF (Sender Policy Framework)
What it is:
This confirms that you are allowed to send emails from your domain. It tells the receiving server, “Hey, these are the official places my emails should come from.”
Why it matters:
Without an SPF record, anyone can pretend to be you, and inboxes won’t know the difference.
✅ DKIM (DomainKeys Identified Mail)
What it is:
A digital signature. It proves that your email hasn’t been tampered with along the way.
Why it matters:
It gives your message that “signed, sealed, delivered” credibility. Without it, your email could look suspicious, even if it’s totally innocent.
✅ DMARC (Domain-based Message Authentication, Reporting & Conformance)
What it is:
Your instructions to the email gatekeepers: “Here’s how to handle any suspicious messages pretending to be me.”
Why it matters:
It puts you in control. Without DMARC, the email world has to guess what to do with fakes—often dropping or junking them.
These trust signals don’t just make things safer. They also dramatically improve your email deliverability. When they’re set up correctly, inboxes say, “Cool, we know you. Come on in.”
Want to know if your trust signals are working? Remember your shiny new mail tester tool!
How Do Emails End Up in Spam?
Ever wonder why some emails land right where they should, and others go missing or end up in the dreaded Spam folder?
It’s not random. Inbox providers (like Gmail and Outlook) run your email through a spam filter obstacle course. And if anything looks dodgy, off it goes to Junk Town.
Here are the most common reasons emails get flagged as spam:
- No authentication (SPF, DKIM, DMARC): If your email doesn’t come with the right “papers,” inbox providers don’t trust it.
- Bad sender reputation: If your domain or IP has a history of sending spam (even accidentally), you’re on thin ice.
- Spammy content or formatting: USING ALL CAPS, too many exclamation marks!!! or shady language (like “Get rich quick”) can trigger alarms.
- Sending from a free email address: Sending business emails from something like yourbusiness@gmail.com looks unprofessional, and spam filters know it.
- Low engagement: If people don’t open or click your emails (or worse, report you), your future emails are more likely to be filtered out.
- Dodgy links or attachments: If your email includes suspicious links or bulky attachments, that’s another red flag.
How to Avoid It?
- Set up SPF, DKIM, and DMARC properly.
- Send helpful, relevant content to people who actually want it.
- Use your own domain (like you@yourbusiness.com).
- Keep your list clean and avoid sending to stale or purchased email lists.
Pulling It All Together
What Are SPF, DKIM, and DMARC Really?
So far, we’ve talked about what happens after you hit send, how emails can get lost at the border, and why inboxes don’t just roll out the red carpet for every message.
Now let’s zoom out and connect the dots.
SPF, DKIM, and DMARC are special instructions added to your DNS records—the settings behind your domain name (such as yourbusiness.com).
What Is DNS? (And Why It Matters)
Imagine the internet as a giant white pages (remember those?). Every website has a name that people use, such as captivatewebsites.com.au . Behind the scenes, computers need a number (called an IP address) to locate it.
That’s where DNS comes in.
DNS stands for Domain Name System, and it’s the system that matches names to numbers—so when you type in a web address, your computer knows exactly where to go.
Think of it like this:
- You type in www.captivatewebsites.com
- DNS quietly looks up the IP address. It will be something like 192.0.2.1.
- It then takes you to https://captivatewebsites.com.au/
- I think you will remember ‘captivate websites’ ahead of 192.0.2.1., right!
But DNS doesn’t just direct website traffic. It also handles things like:
- Email routing (where your business emails go)
- Verification records (like SPF, DKIM, and DMARC for email security)
- Subdomains (e.g. shop.yourbusiness.com or blog.yourbusiness.com)
So while you might not see DNS in action, it’s always working in the background—like the switchboard operator of the internet, making sure the right messages go to the right places.
Wrapping It Up: You Don’t Have to Speak Geek
So, what have we learned?
✅ Emails aren’t just emails—they go through customs checks before they’re delivered
✅ DNS is like your website and email’s address book
✅ SPF, DKIM, and DMARC are trust signals that tell email providers, “Yes, I’m legit”
✅ If those signals are missing or broken, your emails might land in spam… or disappear completely
✅ Deliverability isn’t about luck—it’s about setup
The good news? You’re now better informed than most—and that means you can start spotting problems before spending a fortune on support calls or hours chasing ghosts in your inbox.