Send Time Optimization

Send Time Optimization improves email engagement by scheduling emails at the time each contact is most likely to open or click them.

Instead of sending every email at the same time, Groundhogg analyzes historical engagement patterns for each contact and automatically adjusts delivery time to maximize interaction.

Enabling Optimization For a Broadcast

To use Send Time Optimization for a broadcast, you will need to enable the Advanced Features add-on.

Once enabled, while scheduling a broadcast, you will see a toggle switch to enable Send Time Optimization.

How It Works

Groundhogg tracks email engagement over time, including:

• Email sends
• Email opens
• Email clicks

Each interaction is associated with the original email send time and grouped into hourly engagement buckets based on:

• Day of week
• Hour of day

For example:

• Tuesday at 9 AM
• Friday at 3 PM
• Sunday at 8 PM

Over time, Groundhogg builds an engagement profile for each contact and identifies the hours when they are most likely to engage with emails.

Optimization Behavior

When scheduling a broadcast, the user still chooses the desired send time.

Groundhogg then:

1. Looks at the contact’s historical engagement patterns
2. Searches nearby hours around the requested send time
3. Selects the best nearby hour with the strongest predicted engagement
4. Falls back to the original requested time if there is insufficient data or no strong signal

This means the system respects the marketer’s intended schedule while still improving engagement where possible.

Engagement Weighting

Not all interactions are weighted equally.

Groundhogg treats:

• Opens as a positive engagement signal
• First clicks as a stronger engagement signal
• Second clicks as a smaller additional signal
• Additional clicks beyond the second are ignored

This prevents highly active emails from disproportionately influencing optimization.

Intelligent Signal Decay

Older engagement data gradually loses influence over time.

This allows the optimization profile to adapt naturally as a contact’s behavior changes.

For example:

• A contact who previously opened emails in the morning but now engages in the evening will gradually shift toward evening sends.

Neighbor Smoothing

Engagement data is lightly smoothed between neighboring hours.

For example:

• Strong engagement at 9 AM may slightly influence 8 AM and 10 AM

This helps avoid overfitting and improves optimization quality when data is limited.

Fallback Behavior

If Groundhogg cannot confidently determine a better send time, the original requested send time is preserved.

Examples include:

• Insufficient send history
• Insufficient engagement data
• No positive optimization signal

Performance Optimized

Send Time Optimization is designed to scale efficiently across large contact databases.

Instead of recalculating engagement history on every send, Groundhogg maintains lightweight engagement profiles that are updated incrementally whenever contacts interact with emails.

This allows optimization to run efficiently even for large broadcasts.