Definition
Send pacing is the deliberate management of the rate at which emails are dispatched during a campaign. Rather than sending all emails as quickly as the infrastructure allows, pacing spreads delivery over a defined period — minutes or hours — to maintain a consistent sending volume that receiving servers are more likely to accept.
Sudden volume spikes are one of the most common triggers for delivery throttling. A sender that normally dispatches 10,000 emails per hour but suddenly sends 500,000 in the same window will raise alarms at recipient servers. Pacing smooths the flow and makes the sender's behaviour appear stable and predictable.
How Pacing Works
Most email platforms and SMTP services allow configuration of hourly or per-minute send rate limits. The platform divides the total campaign size by the desired delivery window and throttles dispatch accordingly. For example, 100,000 emails sent over two hours would dispatch approximately 833 per minute.
Why It Matters
This matters because the choices you make here show up directly in your results. Pacing smooths the flow and makes the sender's behaviour appear stable and predictable. When this is handled well it supports engagement, delivery, and the trust subscribers place in your brand; when it is neglected, the effects tend to show up in declining performance and harder-to-fix problems further down the line.
Best Practices
- Maintain consistent pacing patterns across campaigns — erratic pacing is almost as harmful as volume spikes
- Set pacing limits below provider thresholds to avoid triggering automatic rate limiting
- Monitor delivery log data during the send to confirm pacing is working as configured
- Adjust pacing during IP warm-up periods, starting slow and gradually increasing over weeks
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Frequently Asked Questions
Good practice here means handling Email Send Pacing in a way that is relevant, timely, and honest for your audience. Send pacing controls the speed at which emails are dispatched across a campaign — avoiding sudden volume spikes that trigger throttling, deferrals or spam filtering. Done well, it improves engagement and builds trust; done poorly, it creates friction that costs you results.
Because it touches the parts of email that drive outcomes: relevance, trust, and delivery. Small improvements compound, while repeated mistakes quietly erode the health of your programme.
The most common problems are treating Email Send Pacing as a one-off task, ignoring what the data says, and copying competitors without testing. All three lead to effort that does not translate into better results.
Compare the metrics it should influence — engagement, conversions, and deliverability — before and after you make changes. Trends over time matter far more than any single send.
It supports the same goal as the rest of your email programme: the right message to the right person at the right time. Aligned with segmentation and automation, it reinforces everything else rather than competing with it.