Soft bounce
A temporary delivery failure.
A soft bounce means delivery failed for a temporary reason such as a full mailbox, greylisting, rate limiting, or a transient server issue. Providers usually retry soft bounces before converting them into final failures.
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 soft bounce, 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.