Bulk Sending Operations

The operational practice at the highest end of volume — 1M+ daily, where the rules change. Per-ISP throttling matters more than aggregate sending rate. List cleaning has different stakes (a 0.1% bad-address rate is 10,000 bounces at 10M sends, enough to trigger reputation events). PowerMTA's vMTA configuration becomes the central tuning surface. This category is small in count but covers the operational reality of senders past the threshold where managed services stop being economical.