Apollo Metric
Sales Engagement
Email Open Rate = (Emails Opened / Emails Delivered) x 100
Email open rate is the percentage of delivered outbound emails from Apollo sequences that recipients open. While affected by email client privacy features like Apple Mail Privacy Protection, it remains a useful directional indicator of subject line effectiveness and sender reputation when tracked consistently over time.
Full guide: definition, formula, and benchmarksApolloSales EngagementEmail Open Rate
Email open rate is the percentage of delivered outbound emails from Apollo sequences that recipients open. While affected by email client privacy features like Apple Mail Privacy Protection, it remains a useful directional indicator of subject line effectiveness and sender reputation when tracked consistently over time.
How to calculate email open rate
Why email open rate matters for Apollo users
Open rate is the first engagement signal in the outbound funnel. If contacts are not opening emails, nothing downstream matters: no clicks, no replies, no meetings. While individual open tracking has become less precise due to privacy pixels, aggregate trends remain valuable for evaluating subject line strategies, send time optimisation, and deliverability health across your Apollo sequences.
Comparing open rates across sequences, reps, and personas reveals systematic differences in how effectively different approaches capture attention. A rep with consistently lower open rates may be using subject lines that trigger spam filters or sending at suboptimal times. These patterns are invisible in Apollo's native sequence views but become obvious when tracked as a metric with historical trends and benchmarks.
Understand and act on email open rate with KPI Tree
Land Apollo email open event data in your warehouse via ETL. KPI Tree aggregates open rates by sequence, step number, rep, persona, and time period, accounting for known privacy pixel inflation where possible.
Add email open rate as an early-stage indicator in your outbound metric tree, positioned between deliverability metrics and reply rate. Assign ownership to individual reps, set alerts for significant drops, and run A/B comparisons across subject line variants to continuously improve performance.
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Connect your existing warehouse where Apollo data already lands.
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Related Apollo metrics
Email Bounce Rate
Sales EngagementMetric Definition
Email Bounce Rate = (Bounced Emails / Total Emails Sent) x 100
Email bounce rate measures the percentage of outbound emails sent through Apollo sequences that fail to reach the recipient's inbox due to invalid addresses, full mailboxes, or domain-level blocks. It is a critical indicator of list quality and sender reputation health.
Email Response Rate
Sales EngagementMetric Definition
Email Response Rate = (Emails Replied / Emails Delivered) x 100
Email response rate measures the percentage of delivered outbound emails that receive a reply from the recipient. Unlike open rate, response rate is a definitive engagement signal that indicates genuine interest or objection, making it one of the most reliable leading indicators of pipeline generation from Apollo sequences.
Email Template Performance Analysis
Sales EngagementMetric Definition
Email template performance analysis evaluates the effectiveness of individual email templates used across Apollo sequences by comparing open rates, reply rates, positive reply rates, and downstream meeting conversion. It identifies top-performing templates and surfaces underperformers that should be revised or retired.
Email Timing Optimisation Analysis
Sales EngagementMetric Definition
Email timing optimisation analysis examines the relationship between email send time (hour of day, day of week) and engagement outcomes across Apollo sequences. It identifies optimal sending windows for different personas, time zones, and industries to maximise open and reply rates.
Explore email open rate across integrations
All Apollo metrics
Account-Based Sales AnalysisAccount Penetration RateAverage Deal SizeContact Engagement ScoreContact Lifecycle AnalysisContact Response TimeContact Segmentation AnalysisEmail Bounce RateEmail Response RateEmail Template Performance AnalysisEmail Timing Optimisation AnalysisLead Source Attribution AnalysisLead-to-Opportunity Conversion RateList Quality ScoreMonthly Recurring MeetingsOpportunity Stage AnalysisWin RatePipeline Coverage RatioSales Pipeline VelocitySales Cycle LengthSales Rep Performance AnalysisSequence Completion RateSequence Performance AnalysisTask Completion RateEmpower your team to understand and act on Apollo data
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