Poor email deliverability significantly undermines revenue and customer retention
Email is still dominating as a marketing channel, with good reason. It’s direct, scalable, and relatively cost-effective. But here’s the problem: a lot of companies are investing heavily in email campaigns that never reach the people they’re supposed to. If your message doesn’t land in the inbox, it’s just noise, and wasted budget.
The numbers paint a clear picture. According to a report from Kickbox, 64.6% of companies say that poor email deliverability has directly hurt their revenue or customer retention. That’s not a minor flaw. It’s a core systems issue. Many businesses spend over a quarter of their marketing budget, roughly 26.6%, on email marketing. Yet most aren’t doing the necessary work to ensure those emails avoid spam filters and actually show up in inboxes.
This is more than a tech problem, it’s an executive decision point. If your messages don’t get delivered, you don’t get clicks. No clicks mean no conversions, and no conversions mean the relationship between you and the customer weakens. That’s a leakage point in any digital strategy you can’t afford to ignore.
Fixing deliverability demands operational discipline. That means tightening up list management, verifying sender reputation, and making consistent inbox testing a normal part of your process. This isn’t about marketing gimmicks, it’s infrastructure. Get the basics right, and the upside is obvious: higher open rates, stronger brand trust, and better returns from campaigns you’re already running.
Executives who are serious about performance should be just as serious about the pipes that carry their message. Email isn’t going anywhere. Make sure yours arrives.
Spam filters represent the primary barrier to successful email marketing campaigns
When businesses invest in email marketing, they assume the message will reach the customer. But more often than not, it doesn’t. Spam filters are taking out a huge portion of legitimate marketing emails before they ever get seen. It’s a silent breakdown in communication, and most teams aren’t doing enough about it.
The data backs this up. In the same Kickbox report, 60.3% of businesses said spam filtering is their top barrier to getting emails delivered. That’s the majority of marketers acknowledging that algorithms, not people, are blocking their outreach. And most companies are still pushing forward with campaigns without adjusting their strategies to fix it.
Spam filters trigger when emails hit certain red flags: poor list hygiene, lack of authentication, aggressive phrasing, or an inconsistent sending pattern. These systems do what they’re designed to do, protect users. But if your company’s messages are consistently flagged, it damages your domain reputation, and over time, fewer of your emails even get the chance to be opened.
For leadership, this isn’t something to delegate and forget. Performance marketing is only as good as its infrastructure. You can write compelling content and target the right audience, but if you’re repeatedly flagged as spam, you’re operating at a disadvantage that’s compounding over time.
What matters now is precision. This includes authenticating your sender domain (using protocols like SPF, DKIM, and DMARC), monitoring engagement metrics, and adjusting cadence based on recipient behavior. These aren’t optional. They’re core functions of deliverability in 2024.
Executives who treat email like a system, one that needs constant attention, testing, and iteration, are gaining more attention in crowded inboxes. It’s less about more emails, and more about smarter delivery.
Inadequate email list verification exacerbates deliverability challenges and reduces campaign effectiveness
If your email list is polluted with invalid or outdated contacts, you’re not just reducing the effectiveness of your campaigns, you’re actively damaging your ability to reach real people. Every time an email bounces or lands in a spam trap, it signals to inbox providers that your domain isn’t trustworthy. That signal compounds over time, hurting your sender reputation and reducing future deliverability.
The numbers are clear here. Kickbox reports that only 23.6% of businesses verify their email lists before sending out each campaign. That’s a major oversight, especially considering the financial commitment involved, businesses are spending an average of 26.6% of their marketing budgets on email. Skipping list verification just reduces the return on that investment.
This isn’t a resource problem. List hygiene tools and validation services are readily available, scalable, and simple to deploy. The issue is prioritization. Many teams are still chasing volume, more leads, more sends, without securing the basics. The result is higher bounce rates, lower engagement, and reduced inbox placement.
For executives, this is where focus needs to shift. Email list hygiene should be treated as an ongoing operational function, not a one-time setup. You measure your CAC and LTV, this should be on the same operational level of scrutiny. Verified email data improves campaign performance, strengthens sender reputation, and reduces risk. All measurable outcomes that matter to a C-suite audience.
Cleaning your data isn’t a task for later. It’s a performance enabler right now. If your lists aren’t accurate, your campaigns aren’t optimized, and your return is capped before you hit send.
Invalid email entries from webforms diminish lead quality and overall campaign efficiency
Webforms are often the first contact between a business and a potential customer. But if the data collected is flawed from the start, everything downstream suffers. Invalid email addresses, typos, fake submissions, or unusable formats, waste marketing resources and distort performance metrics. You think you’re growing your list, but you’re scaling noise, not leads.
Kickbox’s report shows that 9% of emails captured via webforms are invalid. That means nearly one in ten leads entering your funnel is unusable. Over time, this degrades list quality, increases bounce rates, and impacts sender reputation. The result: even your valid prospects become harder to reach.
The underlying problem is often a lack of real-time validation at the point of data entry. Without automated checks, bad data slips through unchecked and grows with each submission. Many teams collect it and move on, until deliverability suffers and inbox placement drops.
For executives focused on pipeline accuracy and revenue forecasting, this matters directly. Invalid contacts distort your conversion metrics and lead to wasted outreach cycles. They also make it hard to assess true engagement and campaign ROI. Fixing this begins at the top of the funnel, where data hygiene needs to be built in, not added after.
Smart use of input validation, CAPTCHA filters, third-party verification APIs, and periodic audits can solve most of this at scale. This doesn’t require complexity, just discipline. It’s about treating all inbound data as critical infrastructure, not an optional checkpoint.
Good data equals effective marketing. Bad inputs slow you down and cost you reach. If your webforms aren’t being validated in real-time, you’re not managing lead quality with the level of precision today’s deliverability environment demands.
Key highlights
- Inbox placement is a revenue driver: Over 64% of businesses report that poor email deliverability directly impacts revenue or retention. Leaders should treat inbox performance as a critical business metric, not just a marketing KPI.
- Spam filters are blocking growth: 60.3% of businesses face major challenges getting past spam filters. Executives must ensure their teams implement authentication protocols and follow compliant send practices to protect campaign reach.
- List hygiene is a strategic priority: Only 23.6% of companies verify email lists before each campaign, exposing them to bounces and spam traps. Prioritize regular list validation to maintain sender reputation and optimize marketing returns.
- Bad data weakens the funnel: Nearly 9% of emails collected through webforms are invalid, undermining lead quality from the start. Leaders should enforce real-time validation at data entry points to improve efficiency and protect downstream performance.
