Why is sending volume and timing important for cold email deliverability?

Mailbox providers analyze sending patterns to identify bulk or automated email. Volume and timing are key signals.

Volume signals:

Sudden spikes suggest campaign launches, not organic communication

Sustained high volume from new senders indicates bulk operations

Volume exceeding typical human capacity raises flags

Timing signals:

Perfectly timed sends (exactly every X minutes) indicate automation

Sending outside normal business hours may seem suspicious

Consistent patterns day after day suggest programmatic sending

Why these patterns matter:

Human senders have variable patterns

Automated systems produce detectable regularity

Bulk senders often have poor engagement ratios

High volume with low engagement strongly suggests spam

Optimal approach:

Keep volume within sustainable limits

Add variation to timing and intervals

Ramp gradually rather than launching at full volume

Match patterns to what engaged recipients would generate

The harbor master notices when ships arrive in suspiciously regular formation.