Verification by use case
What to verify, when, and what to do with valid, risky and invalid results depends on where the list came from. Each page covers one job: the risks specific to it, a workflow from source to send, which results to keep or drop, and the tools and guides that go with it.
Outbound and prospecting
Lists you built or sourced yourself, sent to people who have not heard from you yet.
- Cold emailVerify a cold email list before it reaches Instantly, Smartlead or lemlist: what to do with catch-all and role addresses, and the published bounce lines that pause campaigns.
- B2B lead listsWhy a vendor's 'verified' label is not enough, how company mail platforms change your results, and how to turn a raw B2B lead export into a list you can use.
- RecruitingVerify candidate emails from an ATS or CV database, reach hiring managers at client companies, and normalise candidate phone numbers before texting.
- Real estateReal estate lists mix portal inquiries, open-house sign-in sheets and past clients. Verify emails before drip campaigns and check phone line type before texting.
- Trade show and conference leadsFor exhibitors: clean badge-scan exports and business-card data, recover failed addresses with the email finder, and why a bought attendee list is a different problem.
- SDRs and sales developmentA workflow for SDRs and sales development teams: verify exported prospect lists before enrolling them in a sequence, handle catch-all and role addresses, and keep bounces off the team's domains.
Marketing and customer lists
Subscribers, customers and donors who opted in, sometimes years ago.
- EcommerceHow online stores lose order emails to typos, give welcome discounts to throwaway addresses, and why Yahoo customers always look risky. A two-checkpoint verification workflow.
- NewslettersWhen to verify a newsletter list (imports, platform migrations, re-engagement), why Yahoo subscribers always look risky, and why engagement, not verification, catches recycled spam traps.
- Marketing agenciesAgencies send lists they did not build. Verify each client list before its first campaign, audit the client's sending domain, and re-verify without metered costs.
- NonprofitsVerify donor and supporter lists before major appeals, keep donor records when email fails, and route those donors to post or phone instead.
- CRM cleanupExport CRM contacts, verify every email, and write the status back as a property your workflows can filter on. Plus phone normalisation in the same pass.
- Purchased listsVerification removes dead addresses from a bought list but can't detect spam traps or create consent. What the platforms' policies say, and what to do if you already bought one.
- Reactivating old listsA list that hasn't been mailed in a year needs verification, a re-permission email sent in small batches, and a clear stop rule. What verification can't see on old lists.
- B2B marketersHow B2B marketers keep nurture lists clean: verify gated-content leads, event and partner imports, and old segments before they hit your ESP or marketing automation.
- Data teamsHow data and ops teams dedupe and validate email columns: normalise, remove duplicates, verify in bulk or through the API, and store status and reason for downstream use.
Signups, forms and inbound leads
Addresses typed into your own forms, checked as they arrive.
- SaaS signupsVerify signup emails through the API before creating an account. Which results to block, why blocking 'risky' turns away real customers, and how to fail open.
- Event registrationsFor event organisers: catch registration typos while there's time to fix them, and verify the attendee export before post-event marketing.
- Marketing automationAutomated flows send the moment a contact arrives. Verify at the point of entry with the API, Zapier or Make, and gate flows on the result.
- Webinar leadsWebinar registrants trade an email for a replay. Verify on registration, send joining links only to real inboxes, and route only valid business addresses to sales.
- Affiliate and lead-genWhen partners send you leads, dead and throwaway addresses are money paid for nothing. Verify at intake, put the rule in partner terms, and reconcile by source.
- Lead forms (API)Verify a lead form's email (and phone) on submit, show a helpful error while the visitor is still on the page, and store the status with the lead.
- Fake signup preventionStop fake and mistyped signups at the form with a server-side email check: which results to block, which to allow, how to fail open, and what verification cannot catch.
- Free-trial abuseReduce repeat free trials with an email check at signup: disposable domains, plus-address and dot variants, and the account rules that email verification cannot replace.
Phone lists
Numbers for texting and calling, normalised and typed before you dial.
- SMS marketingNormalise numbers to E.164, drop numbers that can't exist, and find the mobiles before an SMS campaign. What a phone check can and can't tell you.
- Call centersClean dialer lists before they're loaded: E.164 for the right country code, drop impossible numbers, and split mobiles from landlines with live carrier lookups.