How to lower email bounce rate before a campaign
Hard bounces hurt domain reputation and ESP metrics. A practical checklist: list verification, risky segmentation, and send timing.
Bounce rate is the share of undelivered messages. Hard bounces (invalid, dead domain) are the most damaging — ESPs treat them as a list quality signal.
Where high bounce comes from
- importing old leads without verification,
- forms without validation (typos, disposable),
- recipients changing jobs — addresses expire,
- purchased lists without consent.
One campaign to a dirty database can hurt deliverability for weeks, even on valid segments.
Pre-send checklist
- Verify CSV — remove invalid before importing to Mailchimp / GetResponse / HubSpot.
- Segment risky — catch-all and disposable separately; do not mix with main cold outreach.
- Re-verify — lists unused for 2+ months need a fresh check.
- Signup API — POST /verify in forms protects new leads from day one.
- Domain warm-up — after cleaning, increase volume gradually.
What to remove for sure
| Status | Action |
|---|---|
| Invalid | Do not send — remove from list |
| Disposable | Block at signup; remove from existing database |
| Catch-all (risky) | Business call — test segment or remove |
| Unknown | Re-verify after 24 h or flag for manual review |
Cost
In EmailVerifier 1 credit = 1 address. Pay-as-you-go with no subscription — cheaper than one ESP deliverability incident after a 5% hard bounce campaign.
Upload in the dashboard, download CSV with statuses, import the clean segment back to your ESP.