IP warming
Gradually ramping volume on a new IP to build reputation.
Mailbox providers (Gmail, Outlook, Yahoo) treat brand-new IPs with suspicion. Warming means sending small volumes for the first weeks, ramping up gradually, and prioritizing engaged recipients. Required for dedicated IPs and self-hosted setups.
reading this as SaaS product teams
A SaaS product sends on behalf of its customers, so the deciding factors are tenant isolation, whether suppressions can be scoped rather than global, and whether support can answer why one specific account did not receive one specific email. Lifecycle automation and transactional sending usually need to coexist.
Applied to ip warming, that means weighing multi-tenant support, event stream, the suppressions API, and operating track record ahead of the rest, against trial expiry notices, dunning, onboarding sequences, and per-tenant transactional mail.