What is throttling, and why is it important for deliverability?

Throttling means limiting how fast you send emails. It's essential for cold email because mailbox providers monitor sending velocity as a spam indicator.

• Why throttling matters:
• Sudden volume spikes trigger defensive filtering
• Human senders don't send 100 emails per minute
• Receiving servers impose rate limits and reject excessive connections
• Gradual sending distributes load and appears more natural
• How throttling works:
• Spread daily volume across business hours
• Add random delays between individual sends
• Respect per-domain limits (don't send 50 messages to the same company simultaneously)
• Adjust based on bounce and deferral signals

Practical implementation: Most cold email tools handle throttling automatically. Configure sending schedules that span several hours. If you see 421 rate limit errors, you're sending too fast.

A ship entering harbor at full speed raises alarms. Approaching at measured pace signals legitimate intentions.