How GTM Inboxes uses this term
GTM assigns managed sending IPs so reputation can be monitored per address, polls blacklist and health signals adaptively, and can rotate a listed IP through an approval-gated recovery workflow.
How to choose
Low-volume senders sometimes benefit from shared pools because there is not enough traffic to establish a reputation alone. Sustained cold outbound usually favors dedicated addresses so reputation, evidence, and recovery stay within the operator's control.
Capacity planning
Dedicated IPs make per-IP volume a planning input. Model daily volume per IP conservatively and add addresses before pushing volume, rather than saturating one address and reacting to reputation damage.