Dedicated IP

What it means

M3AAWG defines a dedicated IP as a static address used to send email for one sender, company or brand, which is responsible for everything sent from it and is usually named in its reverse DNS. AWS SES leases dedicated IPs for an additional cost and says they give complete control over sender reputation and let you isolate the reputation of different mail streams.

M3AAWG lists reasons to choose one: isolating a sender whose list quality is unknown or poor, protecting a high-quality sender from others, controlling volume, and meeting requirements of third-party certification. The costs are a warm-up period, since a new IP has no history, and the need for consistent volume, which IP reputation depends on.

The advantages M3AAWG gives for shared environments (steady combined volume, diluted mistakes, lower cost) are why a small or irregular sender may be better served by one.