What is an IP warm-up pool? A Clear Guide

A warm-up pool is a schedule of gradually increasing volume on a new IP so mailbox providers build trust before full sending.

Why it matters

Knowing an IP warm-up pool helps you land in the inbox. See the deliverability checklist.

How Rainmail helps

Rainmail sends from your own domain on a dedicated, isolated IP with SPF, DKIM, DMARC, reverse-DNS and managed warm-up handled for you, plus a REST API and an AI watching deliverability — and it welcomes senders SES, SendGrid and Mailchimp reject, from $8. Run the free checker or see plans.