Senly detects automatically:
- Hard bounces (invalid address, mailbox does not exist) — the address goes on the bounce list, and future campaigns skip that address.
- Soft bounces (mailbox full, server temporarily down) — Senly tries 3 more times spread over 24 hours.
View the bounce overview under Email → Lists → Bounces. There you can remove addresses manually from the bounce list (only do this if you are sure the address works again — otherwise you damage your domain reputation).