There are only two things you can do with an unvalidated risky segment, and both cost you something.
Option 1 — discard them. The segment is frequently as much as 42% of a lead list. Throwing it away means paying to acquire those contacts and then never contacting them. It is the safe choice for your domain and an expensive one for your pipeline.
Option 2 — send to them anyway. This is the more damaging option. Unvalidated risky addresses produce hard bounces, and a high bounce rate does lasting harm:
- Your domain reputation drops with mailbox providers
- Deliverability falls for the addresses that were fine, not just the bad ones
- Sending platforms may suspend or shut down the account
- Recovering a burned domain takes far longer than it took to burn
Validating first is what lets you avoid choosing. You keep the deliverable portion of the segment and drop only what is genuinely dead.