DMARC alignment
The domain match DMARC checks after SPF or DKIM passes.
DMARC does not only ask whether SPF or DKIM passed. It asks whether the passing domain aligns with the visible From domain. SPF alignment compares the Return-Path domain to the From domain. DKIM alignment compares the d= signing domain to the From domain.
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 dmarc alignment, 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.