Deliverability ยท 7 min read

Why Sending Time Patterns Trigger Spam Filters

Bots send at perfect intervals, humans don't

Research shows 30-40% of email opens are from security bots. Learn how AI-driven filters detect automation and what the 0.3% spam threshold means for your campaigns.

  • 84% global inbox rate
  • 0.3% spam threshold

Email Volume vs Spam Rate

How monthly sending volume correlates with spam placement

Monthly VolumeSpam RateInbox Rate
< 10,00018.2%81.8%
10,000 - 50,00022.4%77.6%
50,000 - 200,00029.3%70.7%
200,000 - 1M24.1%75.9%
1M+16.2%83.8%

Source: GetResponse Email Benchmarks (2024)

Frequently asked questions

What is the best time to send cold emails?

Research shows Tuesday through Thursday between 9-11 AM in the recipient's local timezone yields the highest engagement. However, testing with your specific audience is essential as optimal times vary by industry and recipient behavior.

Does sending time affect spam filtering?

Yes, sending patterns influence spam detection. Sudden spikes in volume, sending at unusual hours, or patterns that look automated can trigger spam filters. Consistent, human-like sending patterns during business hours perform better.

Should I send all my emails at once or spread them out?

Always spread emails throughout the day to mimic natural sending behavior. Batch sending looks automated and can trigger spam filters. Use sending limits of 50-100 emails per hour maximum for cold outreach.

Does the day of the week affect email deliverability?

Day of week primarily affects engagement rather than deliverability. However, since engagement impacts sender reputation, sending on high-engagement days (Tuesday-Thursday) indirectly supports better long-term deliverability.