Transactional and lifecycle mail share a brand, so one bad campaign can degrade password-reset delivery.
What email bounce handling is#
Bounce handling is the automated processing of delivery failure notices (DSNs) to classify hard versus soft bounces and suppress addresses accordingly.
Why it matters#
Repeatedly sending to invalid addresses is one of the strongest negative reputation signals providers track.
Implementation plan for SaaS companies#
- Parse DSN codes: 5.1.x means the address does not exist (hard); 4.x.x means temporary (soft).
- Suppress hard bounces after one failure and soft bounces after three.
- Route bounce notifications to a monitored mailbox or webhook.
- Review bounce reasons weekly for patterns like 'blocked' that indicate reputation issues.
Priorities specific to SaaS companies#
Transactional and lifecycle mail share a brand, so one bad campaign can degrade password-reset delivery. Weight your effort toward the steps above that address this constraint first, and measure with metrics that match how SaaS companies generate value from email.
Common mistakes#
- Treating 'mailbox full' as a hard bounce and losing valid contacts.
- Ignoring 'blocked by policy' bounces that signal a blocklist or DMARC failure.
Frequently asked questions#
What is the difference between a hard and soft bounce?
Hard bounces are permanent failures (bad address). Soft bounces are temporary (full mailbox, server down). Suppress hard immediately.