Apollo gives you contacts. Confidence scores are not deliverability guarantees.
Apollo.io is one of the most widely used B2B sales intelligence platforms. Its contact database, enrichment capabilities, and outreach features make it a standard part of many sales tech stacks.
Apollo's email confidence score reflects how certain Apollo's systems are that the address matches a contact based on domain patterns, public data signals, and historical accuracy. A high score means the pattern is common and consistent. It does not mean the specific mailbox is currently active.
The difference matters most when running campaigns at scale. Apollo may show 10,000 contacts with 80%+ confidence scores. Of those, a meaningful percentage may include catch-all domains, stale records from employees who left, role-based inboxes, and duplicate entries — none of which the confidence score distinguishes. Verifying before import rather than after the first send is the only way to find out before it damages sender reputation.
B2B Leads Verification Framework
This page covers one database or workflow. The full framework explains the complete path from B2B data source through verification, segmentation, and routing into your CRM or sender.
What Apollo's data model produces.
Apollo combines several data sources to build contact records: public profile data, company websites, enrichment from third-party providers, and community-sourced updates. Each source has different update cycles and accuracy characteristics.
| Apollo data source | Update frequency | Email accuracy profile |
|---|---|---|
| Public LinkedIn profiles | When Apollo re-indexes | High for current employees, lower for recent movers |
| Company websites and directory pages | Variable | Accurate at time of scrape, may drift |
| Third-party enrichment providers | Provider-dependent | Varies by provider and industry |
| Community verification signals | Continuous but sparse | Improves popular domains, limited for SMBs |
This mixed-source model means a single export can contain addresses from records last updated at very different times. A high confidence score indicates Apollo's internal consistency check passed — it does not indicate when the underlying data was last verified against a live mail server.
What Apollo's confidence score actually measures.
| Apollo confidence level | What it means | What it does not mean |
|---|---|---|
| High (90%+) | Address matches the most common pattern for this domain | Mailbox is currently active and will accept email |
| Medium (70–89%) | Address likely matches, with some uncertainty | Address has not changed since Apollo collected it |
| Low (under 70%) | Pattern match is less reliable | Address exists at all |
| Not shown (unlabeled) | Address sourced without confidence scoring | Higher risk — treat as unverified |
Apollo derives confidence scores from domain email patterns, profile data, and other signals available at the time of collection. Addresses change when employees leave, when companies restructure, and when domains update their mailbox configurations. None of those changes are automatically reflected in the confidence score.
The specific risks in an Apollo export.
| Risk | Source | Impact |
|---|---|---|
| Invalid addresses | Employees who left after data collection | Hard bounces |
| Catch-all domains | Companies that accept all incoming email | Uncertain delivery, inflated list size |
| Role-based inboxes | sales@, info@, support@ from company pages | Shared inbox, no named contact |
| Stale personal emails | Old LinkedIn data imported into Apollo | Wrong person or inactive address |
| Duplicate contacts | Multiple Apollo searches across overlapping lists | Repeat sends, complaint risk |
| Low-confidence guessed addresses | Pattern-matched without direct verification | Higher probability of non-existent mailbox |
Common failure patterns for Apollo exports without verification.
Teams that skip the verification step before importing Apollo exports tend to hit the same sequence of problems:
- Launch campaign against large export
- Initial bounce rate looks manageable because servers have not yet flagged the domain
- Catch-all ambiguity means many addresses appear to deliver but reach inactive mailboxes
- By mid-campaign, hard bounce rate climbs above safe threshold
- Sender reputation score drops, affecting inbox placement for subsequent sends
- Reply rates fall because a portion of "delivered" messages are sitting in catch-all black holes
The cost compounds across campaigns. Cleaning sender reputation after multiple high-bounce sends requires weeks of low-volume warm-up sends and may require new sending infrastructure.
Verify Apollo exports before import.
The right workflow for any Apollo export is to run it through BillionVerify before it reaches a CRM, sender, or sequence. Not after the first campaign wave. Not when bounce rate starts climbing.
Export from Apollo
→ Normalize and deduplicate
→ Remove previously suppressed addresses
→ Verify with BillionVerify
→ Route by signal
→ Import valid records into CRM or sender
→ Send
Route each result.
| BillionVerify result | Action for Apollo exports |
|---|---|
| Valid | Import into CRM or target campaign |
| Invalid | Do not import — add to suppression |
| Catch-all | Separate segment, lower volume, monitor closely |
| Role-based | Separate campaign with shared-inbox messaging |
| Unknown | Review — exclude from high-volume sequences |
| Risky or disposable | Do not import |
After verification — where records go.
- Valid: import into CRM, standard sequence
- Catch-all: lower-volume segment, separate from main campaign, monitor reply rates and soft bounces
- Role-based: separate campaign, messaging written for shared inbox — no single-reader personalization
- Invalid and disposable: suppression file, never re-import
- Unknown: review queue, decision required before any send — exclude from automated sequences
Re-verification schedule for Apollo lists.
| List age | Recommended action |
|---|---|
| Under 30 days | Run verification before first use if not already done |
| 30–90 days | Re-verify if being used for a second campaign |
| 90 days or older | Always re-verify before any use |
| 6 months or older | Re-verify and expect meaningful percentage of invalids |
Apollo does not update your saved lists when contacts change employers or companies update their email infrastructure. Time is the primary variable in Apollo export quality.
Hunter Email Verification
Understand what Hunter verification covers and when to run an independent check.
ZoomInfo Email Verification
Verify ZoomInfo contacts before import — confidence scores are not the same as deliverability.
RocketReach Email Verification
Verify RocketReach exports before sending — catch-all and stale records need a final check.
Lusha Email Verification
Verify Lusha contacts before import — especially for EMEA and LinkedIn-sourced records.
Seamless.AI Email Verification
AI-discovered addresses still need verification — confirm deliverability before import.
Snov.io Email Verification
Verify Snov.io finder output before sending — pattern-based discovery produces mixed-quality results.
UpLead Email Verification
Verify UpLead contacts before import — small team exports need the same verification gate.
Cognism Email Verification
Verify Cognism exports before sending — enterprise EMEA data still requires a deliverability check.
GetProspect Email Verification
Verify GetProspect output before import — LinkedIn-sourced contacts need a final deliverability gate.
Adapt.io Email Verification
Verify Adapt.io contacts before sending — database exports require an independent verification pass.
Lead411 Email Verification
Verify Lead411 contacts before import — intent signals do not guarantee email deliverability.
ContactOut Email Verification
Verify ContactOut exports — LinkedIn-sourced emails need a final deliverability check before outreach.
SalesQL Email Verification
Verify SalesQL output before sending — LinkedIn finder results need a final verification gate.
Wiza Email Verification
Verify Wiza exports — LinkedIn Sales Navigator workflow output requires a deliverability check.
Findymail Email Verification
Verify Findymail output before import — confidence scores are not the same as deliverability.
Kaspr Email Verification
Verify Kaspr contacts before sending — LinkedIn-sourced emails require a final quality check.
Skrapp Email Verification
Verify Skrapp output before import — pattern-based email discovery requires a verification pass.
Voila Norbert Email Verification
Verify Voila Norbert output before sending — finder confidence does not equal SMTP deliverability.
AeroLeads Email Verification
Verify AeroLeads exports before import — mixed-source data requires a final deliverability gate.
Datanyze Email Verification
Verify Datanyze contacts before sending — technographic signals do not guarantee deliverability.
Dropcontact Email Verification
Verify Dropcontact enriched data — enrichment accuracy is separate from current deliverability.
SignalHire Email Verification
Verify SignalHire contacts before sending — sourced data needs a final deliverability check.
Prospect.io Email Verification
Verify Prospect.io contacts before import — automation platform data needs a separate verification pass.
Saleshandy Leads Verification
Verify Saleshandy lead data before sending — platform-sourced contacts need a final quality check.
Clearbit Enrichment Verification
Verify Clearbit enriched emails before sending — enrichment signals are not SMTP deliverability.
Apollo email verification common questions.
1. Does Apollo verify emails before I export them?
Apollo runs its own confidence scoring on email addresses as part of its data enrichment process. That scoring is a quality signal for Apollo's database, not a real-time SMTP check. Running a BillionVerify pass after export catches what Apollo's confidence score cannot — current deliverability, catch-all status, and addresses that changed after Apollo's last data update.
2. What is a good confidence score threshold for Apollo exports?
There is no threshold that eliminates the need for verification. Even 90%+ confidence addresses can include catch-all domains, stale records, and role-based inboxes that produce bounces. Use the confidence score as a pre-filter if you need to reduce list size, but always verify the resulting list before import.
3. How should I handle catch-all addresses from Apollo?
Route them to a separate, lower-volume segment. Do not mix catch-all addresses with confirmed valid addresses in the same high-volume rotation. Some catch-all addresses will deliver; many will not. Separating them protects your main campaign's deliverability metrics and keeps performance data clean.
4. Should I re-verify an Apollo list from a previous campaign?
Yes. Any Apollo export older than 90 days should go through verification again before reuse. Addresses that were valid when you last used the list may have changed. Apollo does not automatically update your saved lists when contact data changes.
5. What export format from Apollo works best with BillionVerify?
Export as CSV from Apollo. BillionVerify accepts CSV files with an email column. No special format is required — a standard Apollo contact export with the email field included is ready to verify without transformation.
6. How do I handle Apollo exports that include both business and personal emails?
Verify both. Business addresses go through the standard routing table. Personal addresses (Gmail, Outlook, Yahoo) should be flagged separately — they are not appropriate for B2B outbound in most campaigns, and including them in high-volume sequences can trigger spam filters more quickly than domain-matched business addresses.
7. What percentage of an Apollo export typically passes verification?
It depends on list age, industry, and contact type. Recent exports from large, stable company domains tend to have higher valid rates. Lists with many SMB contacts, recent job changers, or catch-all-heavy industries (technology, startups, agencies) tend to have more catch-all and invalid results. Do not use an expected pass rate to decide whether to verify — verify every export regardless of anticipated quality.
8. Can I use Apollo's built-in email verifier instead of BillionVerify?
Apollo does include an email verification feature in some plan tiers. It checks format, domain existence, and some deliverability signals. It does not perform the same SMTP-level check that BillionVerify runs at import time, and it does not classify catch-all, role-based, and unknown signals with the same granularity. For lists going into high-volume campaigns, running BillionVerify as a separate gate after Apollo reduces risk that Apollo's internal tool does not fully catch.