Understanding Copy Testing: Methods, Examples, and Best Practices

Why deliverability is the foundation of your funnel

Ever wonder why your perfectly crafted sales pitch gets zero replies? It's probably cuz it never even hit the inbox, which is a total buzzkill for any saas founder.

If you're building a funnel but ignoring how emails actually land, you're basically pouring water into a bucket full of holes. Deliverability isn't some boring IT task; it is the actual floor of your entire sales operation.

Think about it—if they don't see it, they definitely can't buy it. When your emails start hitting the "Promotions" tab or worse, the spam folder, your cost per lead (CPL) goes through the roof because you're paying for data and tools that aren't performing.

• Vanishing ROI: You spend thousands on a healthcare marketing list, but if 30% of emails bounce or get blocked, you just set a third of your budget on fire. (You LOSE 30% of email sales if these are not set-up and ...)
• Brand Damage: In industries like finance, if a client expects a login link and the email never arrives in their inbox, they don't just get annoyed—they stop trusting your security.
• The connection spiral: If your app's method of connection to an Email Service Provider (ESP)—the api—is shaky, your transactional emails like password resets fail. Then your support team gets buried in "where is my email?" tickets.

According to a report by Validity, about 1 in 5 emails fail to reach the inbox. That’s a massive chunk of potential revenue just... gone.

I've seen saas teams obsess over button colors while their sender reputation was trashed. It’s painful to watch. Since the "send" button doesn't guarantee a "read," we need to look at how deliverability shifts as leads move through your sales stages.

Deliverability at the top of the funnel (TOFU)

Ever wonder why that first welcome email you sent to a new lead just... vanished? It’s like showing up to a first date and getting stuck in the revolving door while they’re already at the table.

At the top of the funnel (TOFU), deliverability is your digital handshake. If your IP reputation is shaky or your list is full of junk, you’re failing before you even say hello.

When you’re pulling in new leads—whether it's from a whitepaper download in healthcare or a signup for a retail newsletter—the speed and placement of that first email is everything. If it lands in spam, they’ve already forgotten you.

• Nailing the welcome email: This is your highest engagement moment. If your technical setup isn't right, your "Welcome!" note becomes "Who are you again?" because it never arrived.
• IP Reputation for cold outreach: If you’re doing B2B prospecting, your sender reputation is like a credit score. Send too much too fast from a new sending domain or IP address, and the filters will crush you.
• Email verification is a must: You gotta clean those lists early. According to Snov.io, maintaining a bounce rate under 2% is critical because high bounces tell providers you're a spammer. (Email bounce rate: Definition, benchmarks, and how to lower it)

I've seen retail brands lose thousands in "first-purchase" revenue because their discount codes went to the junk folder. It's a tragedy. Keeping your list clean from the jump saves you a massive headache later, especially when you start getting into the more complex automation stuff.

Middle of the funnel (MOFU) and nurturing

So you’ve got them to sign up, right? Now comes the hard part—keeping them interested without being that annoying person who won't stop texting.

In the middle of the funnel (MOFU), your emails are doing the heavy lifting to turn a "maybe" into a "yes." But if your automation triggers are slow or your api connection is acting up, those nurturing sequences fall apart. If a lead in the finance sector asks for a whitepaper and it takes six hours to arrive because of a delivery lag, they've already moved on to a competitor.

When you're running complex workflows, timing is literally everything. I've seen saas founders build these beautiful 10-step drip campaigns, but they forget that every step is a chance for the mail to get lost. If your engagement drops, it’s often not the content—it's that the emails are hitting the "Promotions" tab where they go to die.

• Personalized workflows: You gotta use data to trigger the right message at the right time. If someone clicks a pricing page link, your system should fire off a relevant case study immediately.
• Reliable delivery: For saas providers, using a tool like mailazy is a game changer because it handles the heavy lifting of api delivery. You need that high deliverability so your automated "check-ins" actually show up when the lead is still thinking about you.
• Watch the drop-offs: Use your analytics to see where people stop opening. If step 3 in your sequence has a 0% open rate, your sender reputation might be taking a hit on that specific template.

According to the 2024 Email Deliverability Test by Email Tool Tester, some popular providers struggle to hit even 80% deliverability, which means 20% of your nurturing effort is just wasted. That’s a lot of lost conversations.

Watching a lead go cold because of a technical glitch is the worst. It’s like losing a race because your shoelaces were tied together. Once you've got them engaged, you need to make sure you aren't overstaying your welcome or failing at the most critical moment—the sale.

Bottom of the Funnel (BOFU) and Retention

When you're at the finish line, a missing email isn't just a "glitch"—it's a lost sale. Nothing kills the vibe of a ready-to-buy customer like a broken checkout link or a password reset that never shows up.

At the bottom of the funnel (BOFU), your delivery is less about marketing and more about transactional reliability. If a retail shopper hits "buy" and the confirmation email vanishes, they freak out and call support. Or worse, they just cancel the order.

The final stage is all about trust. If your api connection isn't snappy, you're toast.

• Password resets and invoices: These are the most opened emails you'll ever send. If these hit the spam folder, your saas product is basically broken in the user's eyes.
• Conversion at checkout: A 2023 study by Baymard Institute shows that nearly 70% of carts are abandoned. If your "forget something?" email arrives two days late, that lead is already gone to Amazon.
• Real-time monitoring: You gotta use webhooks to know when things fail. If a high-value invoice bounces, your sales rep needs to know now, not next week.

I've seen finance apps lose users because their 2FA codes lagged by just sixty seconds. People have zero patience these days. To avoid these disasters, we have to look at the actual technical settings that keep your domain healthy.

Technical checks to keep your funnel healthy

Look, you can have the best copy in the world, but if your technical backend is a mess, you're just screaming into a void. It's like trying to mail a letter with no stamps—it just ain't gonna happen.

Getting your technical checks right is the only way to stay out of the "junk" folder. If you haven't set up your spf, dkim, and dmarc yet, you're basically asking filters to block you. These records prove to providers like Gmail that you actually own your domain and aren't some hacker trying to phish their users.

• SPF (Sender Policy Framework): This is a list of servers allowed to send mail for your domain. It’s like an authorized guest list for a party.
• DKIM (DomainKeys Identified Mail): This adds a digital signature to your emails, so the receiver knows the content wasn't messed with during transit.
• DMARC (Domain-based Message Authentication, Reporting, and Conformance): This tells the world what to do if an email fails those first two checks. Start with "p=none" so you don't accidentally block your own legit mail while you're still testing.
• Sender Score: Think of this like a credit score for your ip. A 2024 report by Validity (as mentioned earlier) shows how much reputation impacts reaching the inbox.

Regular testing is way better than trying to fix a trashed reputation after the fact. I've seen saas founders ignore their bounce rates until their entire domain gets blacklisted—don't be that guy. Use feedback loops to see who's marking you as spam and remove them immediately.

At the end of the day, deliverability is about trust. If you respect the inbox, the inbox will respect you. Keep your tech tight, and your funnel will actually do its job. It’s just common sense once you get past the acronyms.