Email Deliverability Loss Calculator
Calculate how many emails never reach the inbox due to spam filters and bounces — and exactly how much revenue you're losing from poor deliverability.
Enter Your Deliverability Data
% landing in spam/promotions
Hard + soft bounces
Total active subscribers
Average revenue per email sent
For monthly loss calculation
Your Deliverability Impact
Emails Not Reaching Inbox
—
Per campaign
Deliverability Rate
—
Reaching inbox
Monthly Revenue Loss
—
From poor deliverability
Annual Revenue Loss
—
12-month projected loss
Email Deliverability Benchmarks
Industry-leading email programmes achieve 95–98% deliverability with bounce rates under 2% and minimal spam placement. Below 90% deliverability indicates serious sender reputation issues.
Excellent Deliverability
95–98%
Healthy Bounce Rate
<2%
Target Spam Rate
<5%
How Deliverability Loss is Calculated
Emails Not Reaching Inbox = List Size × ((Spam Rate + Bounce Rate) ÷ 100)
Deliverability Rate = (Emails Reaching Inbox ÷ List Size) × 100
Lost Revenue per Campaign = Emails Not Reaching Inbox × Revenue per Email
Monthly Revenue Loss = Lost Revenue per Campaign × Campaigns per Month
This calculation combines spam placement and bounces to estimate total inbox failure rate. To improve accuracy, track spam rate using seed testing tools like GlockApps or 250ok.
Why Email Deliverability Matters More Than Open Rates
Most email marketers obsess over open rates and click-through rates, but deliverability is the silent killer that determines whether those metrics even matter. If 20% of your emails land in spam folders or bounce before reaching the inbox, you're losing one-fifth of your potential revenue before a single subscriber has a chance to engage. Deliverability issues compound over time — poor sender reputation leads to more spam placement, which further damages reputation, creating a downward spiral that can take months to reverse.
Deliverability has two core failure modes: bounces and spam placement. Bounces occur when emails can't be delivered due to invalid addresses (hard bounces) or temporary issues like full inboxes (soft bounces). Spam placement happens when inbox providers like Gmail, Outlook, or Yahoo route your emails to spam or promotions folders based on sender reputation, content triggers, or subscriber engagement history. Both failures cost revenue, but spam placement is more insidious because it's invisible — you won't see bounces in your platform, and many marketers never realise their emails aren't reaching the inbox.
Improving Deliverability: The Core Fixes
Deliverability improvement starts with sender authentication — ensuring SPF, DKIM, and DMARC records are properly configured for your sending domain. These protocols verify your identity to inbox providers and are now baseline requirements for reaching the inbox. Next, focus on list hygiene: regularly remove hard bounces, suppress unengaged subscribers who haven't opened in 6+ months, and avoid purchased or scraped lists that poison sender reputation. Finally, optimise engagement by sending relevant, segmented content that subscribers actively want — inbox providers reward high engagement with better placement.
Monitoring Deliverability Over Time
Track bounce rates, spam complaint rates, and inbox placement rates monthly to catch deliverability issues early. Bounce rates should stay under 2%. Spam complaints should be under 0.1%. Inbox placement should exceed 95%. Use seed testing tools to monitor where your emails land across major providers, and investigate immediately if placement drops. Deliverability issues are easiest to fix when caught early — once sender reputation tanks, recovery can take 4–8 weeks of careful list management and sending behaviour adjustments.
Use this calculator monthly to quantify the revenue impact of deliverability issues and justify investment in authentication, list hygiene, and engagement optimisation. When you can show exactly how much revenue poor deliverability costs, fixing it becomes a business priority rather than a technical afterthought.