An email that cannot be delivered is described as a bounce. Mailchimp distinguishes hard bounces, which usually reflect a permanent delivery problem, from soft bounces, which usually reflect a temporary one. The recorded reason matters when deciding what to do next. Source: Mailchimp: Soft and hard bounces

Read the reason before acting

Check the campaign’s bounce report and the platform’s guidance. Correct an address only when there is reliable evidence for the change. This avoids guessing an alternative address and sending a message to someone who was not the intended recipient.

Agree a handling process

Document who reviews failed deliveries and how the mailing platform handles each type. Keep suppression decisions visible to colleagues who import lists. This gives the team a consistent approach and helps prevent an old contact file from undoing a considered decision.

Written and updated by Travelgenix. Sources checked on 19 October 2026. Practical advice and examples are Travelgenix editorial guidance.