Bulk email verification
Clean the list before the list cleans your reputation.
Validate a CSV or API batch, separate valid, invalid, catch-all, disposable, and unknown results, and move only approved addresses into your next GTM step.
A bulk verifier should make uncertainty visible.
A single green status hides too much. Good email-list cleaning preserves the evidence behind each result: whether the domain accepts mail, whether the mailbox responded, whether the domain is catch-all or disposable, and whether the result is current enough for the campaign.
gtmcli keeps those results attached to the row in a visual workspace. You can review exceptions manually, apply a code-column policy, or let a coding agent prepare separate send, suppress, and investigate files.
Verification is a risk-control step, not a delivery promise. Sender reputation, authentication, sending patterns, message relevance, and mailbox changes still affect what happens after validation.
What you can build
One workspace from source to finished workflow.
01
CSV list cleaning
Import a file, map the address column, validate in bulk, and export results with original row context intact.
02
Email validation API
Validate addresses inside signup flows, enrichment systems, and custom applications through a documented endpoint.
03
Catch-all handling
Keep catch-all results separate so your team can apply a deliberate, risk-based sending policy.
04
Disposable detection
Flag temporary and disposable providers before they pollute product, CRM, or campaign data.
05
Provider waterfalls
Combine gtmcli validation with MillionVerifier, BounceBan, ZeroBounce, or another supported provider.
06
Agent summaries
Ask a coding agent to run a batch, explain status counts, and prepare only records that pass your rule.
How it works
Move from raw file to send policy.
- 01
Import and map
Upload the source CSV and identify the email field without discarding the rest of the row.
- 02
Verify every address
Run domain, mailbox, catch-all, disposable, and provider checks at batch scale.
- 03
Apply a written policy
Define which statuses can send, which require more evidence, and which must be suppressed.
- 04
Export with reasons
Preserve result, confidence, and reason fields so downstream teams can audit the decision.
Agent prompt
Validate every address in prospects.csv. Create send.csv for valid business mailboxes, review.csv for catch-all or unknown results, and suppress.csv for invalid or disposable addresses. Include a status summary.
✓ Editable workflow ready for review
Compare approaches
Statuses need different actions
| Status | What it means | Recommended default |
|---|---|---|
| Valid | Mailbox accepted the verification checks | Eligible after campaign and consent rules pass |
| Invalid | Address or domain failed a decisive check | Suppress and correct the source record |
| Catch-all | Domain may accept any local part | Review separately; do not treat as proven valid |
| Unknown | Server response was inconclusive | Retry later or use another evidence source |
| Disposable | Temporary or disposable provider detected | Exclude from most business workflows |
Frequently asked questions
Straight answers before you build.
What is bulk email verification?
Bulk email verification checks a list of addresses for syntax, domain, MX, mailbox, catch-all, disposable, and other deliverability signals. The output should preserve a status and reason for each row so your team can decide what to send, suppress, or review.
Can I upload a CSV to gtmcli?
Yes. CSV import is a supported workflow trigger. You can map the email column, run validation, inspect statuses in the visual workspace, and export or route the accepted rows.
Does email verification guarantee delivery?
No. Verification reduces obvious risk but cannot guarantee delivery, inbox placement, or engagement. Mailbox behavior changes, catch-all domains remain ambiguous, and sender reputation and message quality still matter.
How should catch-all emails be handled?
Treat catch-all as a separate risk class rather than valid or invalid. Use additional evidence, provider confidence, recent engagement, and a conservative sending policy. High-risk campaigns may exclude catch-all records entirely.
Can an AI agent run bulk verification?
Yes. Coding agents can start a CSV or API batch, monitor the job, summarize status counts, and prepare accepted or review files through gtmcli's MCP, CLI, and API interfaces.