This guide walks through the complete process of verifying a bulk email list in Zilch Bounce — from preparing your file to exporting segmented results. Whether you're cleaning a marketing list, a cold outreach database, or a CRM export, the process is the same.
Before You Start: Prepare Your List
Zilch Bounce accepts two file formats for bulk import:
- .TXT — one email address per line, no headers
- .CSV — email addresses in a column; Zilch Bounce will prompt you to select the correct column on import
Clean Up Before Importing
Remove obvious duplicates and fix clear formatting errors (extra spaces, missing @ symbols) before importing. This saves verification credits and speeds up the run.
Step 1: Open the Bulk Verify Tab
Launch Zilch Bounce and navigate to the Bulk Verify tab from the left sidebar. This is where all multi-address list processing happens, separate from the Single Verify tool used for one-off checks.
Step 2: Import Your Email List
Click Import List and select your .CSV or .TXT file. For CSV files, Zilch Bounce displays a column picker — select the column containing email addresses. The preview will show a sample of detected addresses. Verify the count matches your expected list size before proceeding.
Step 3: Start Verification
Click Start Verification. Zilch Bounce begins processing your list using the proprietary deep verification engine. You'll see a real-time progress bar showing emails processed, current status distribution, and estimated time to completion.
Network Resilience
If your connection drops during a large run, Zilch Bounce automatically saves progress. When connectivity is restored, the run resumes from where it left off — you won't lose completed results.
Step 4: Review Results
When verification completes, the results panel shows a breakdown by status:
- Valid — confirmed deliverable mailboxes
- Invalid — non-existent mailboxes, dead domains, or fatal errors
- Risky — catch-all, disposable, or role-based addresses
- Unknown — inconclusive results (greylisting, server timeouts, provider-side blocking)
Click any status category to filter the list to that segment and inspect individual results. Each address shows its specific sub-status (e.g., "Catch-All Domain," "Disposable Provider," "MX Record Missing") to help you make informed segmentation decisions.
Step 5: Export Your Results
Click Export to download your results. You can export the full list with status labels, or export individual segments separately. For most use cases, you'll want to export:
- Valid addresses — your clean send list
- Invalid addresses — add to your suppression list to prevent re-import
- Full results with status column — for CRM sync and audit trail
Step 6: Handle Each Segment
| Segment | What to Do |
|---|---|
| Valid | Import to ESP — safe to send |
| Invalid | Add to suppression list — do not send |
| Disposable | Add to suppression list — do not send |
| Role-Based | Exclude from cold outreach; OK for transactional |
| Catch-All | Send at low volume — monitor bounce rates closely |
| Unknown | Segment separately — test at low volume with opt-in lists |
Step 7: Compare Against Previous Results
If you've verified this list before, use Zilch Bounce's History & Comparison feature to run a differential — comparing the current results against the previous scan. This reveals how many addresses have degraded since the last check and gives you a precise measure of list decay rate.
Use Smart Caching
Zilch Bounce caches results locally and in the cloud. Addresses verified recently don't consume additional processing when re-run — the cached result is returned instantly for addresses that haven't changed.