How It Works
This guide explains The 25-check verification pipeline (22 Quick, 25 Deep), trust scoring, and result categories. so you can complete the TrekMail task with confidence.
Article details
Type, difficulty, plans, and last updated info.
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Article details
Type, difficulty, plans, and last updated info.
- Type
- Reference
- Difficulty
- Beginner
- Plans
- Nano · Starter · Pro · Agency
- Last updated
- May 9, 2026
The TrekMail Email Verifier validates email addresses before you send. Upload a list or use the API — we check every address against up to 25 validation rules and return a trust score.
Quick mode vs Deep mode
The verifier offers two modes:
- Quick mode (default) — runs 22 checks using DNS and pattern analysis. Fast, accurate, and sufficient for most use cases. Costs 1 credit per email.
- Deep mode — runs all 25 checks, including SMTP mailbox verification and spam trap heuristics. Costs 2 credits per email.
Deep mode connects to the recipient mail server to confirm whether the mailbox actually exists. This catches addresses that look valid on paper but will bounce in practice. Use it for purchased lists, important campaigns, or leads from unknown sources.
Note: SMTP verification cannot confirm individual mailboxes on providers that use catch-all configurations (Gmail, Yahoo, Outlook). For these domains, SMTP status will show as "inconclusive" and the score relies on the other checks.
Why verify emails?
- Reduce bounces — hard bounces damage your sender reputation and can get your domain blacklisted.
- Save money — don't waste sending credits on addresses that will never receive your email.
- Improve deliverability — ISPs track your bounce rate. Keeping it under 2% is critical.
What we check
Every email goes through a multi-phase pipeline. Quick mode runs checks #1–21 and #23 (22 checks total). Deep mode runs all 25.
Phase 1: Hard-fail checks (instant reject)
| # | Check | What it does | Mode |
|---|---|---|---|
| 1 | Syntax | RFC-compliant format validation | Quick + Deep |
| 2 | Punycode / IDN | Detects internationalized domain attacks and homograph abuse | Quick + Deep |
| 3 | Disposable domain | 5,000+ known temporary email providers | Quick + Deep |
| 4 | Admin blocklist | Platform-wide blocked domains | Quick + Deep |
| 5 | MX records | Confirms the domain can receive email | Quick + Deep |
| 6 | Routable MX IP | Rejects private/reserved IP ranges (10.x, 192.168.x, 127.x) | Quick + Deep |
| 7 | Bounce suppression | Cross-references known bounced addresses for your account | Quick + Deep |
Phase 2: Soft signals (trust score modifiers)
| # | Signal | Score impact | Mode |
|---|---|---|---|
| 8 | Role-based prefix (info@, admin@) | 0 points (informational flag, no penalty) | Quick + Deep |
| 9 | Gibberish local part (random consonant clusters, mixed random chars+digits) | -15 points | Quick + Deep |
| 10 | Typo suggestion (Levenshtein distance=1 domain correction) | 0 points (informational) | Quick + Deep |
| 11 | Plus-addressing (user+tag@ subaddressing) | -5 points | Quick + Deep |
| 12 | Free provider (Gmail, Yahoo) | 0 points (neutral — known infrastructure) | Quick + Deep |
| 13 | Missing SPF record | -10 points | Quick + Deep |
| 14 | Missing DMARC record | -10 points | Quick + Deep |
| 15 | DNSBL check (Spamhaus DBL / SURBL listing) | -20 points | Quick + Deep |
| 16 | Custom domain bonus (MX + SPF + DMARC on non-free domain) | +5 bonus | Quick + Deep |
| 17 | Domain age < 30 days (RDAP lookup) | -10 points | Quick + Deep |
| 18 | Gravatar existence (single verify only, skipped in batch) | +3 bonus | Quick + Deep |
| 19 | Name detection (recognizable first/last name in local part) | +1 to +3 bonus | Quick + Deep |
| 20 | Profanity detection (offensive language in local part) | -10 penalty | Quick + Deep |
| 21 | Domain web presence (live website on the domain) | +2 bonus / -5 penalty (single verify only, skipped in batch) | Quick + Deep |
| 23 | Breached domain check (domain found in known data breaches) | 0 points (informational) | Quick + Deep |
Phase 3: Deep-only checks
| # | Signal | Score impact | Mode |
|---|---|---|---|
| 22 | Spam trap heuristic (pattern-based spam trap detection) | -10 to -30 penalty | Deep only |
| 24 | SMTP mailbox verification — accepted | +5 bonus | Deep only |
| 25 | SMTP mailbox verification — rejected | Hard fail (score → 0) | Deep only |
Result categories
| Status | Score | Meaning |
|---|---|---|
| Safe | 90-100 | High confidence — send freely |
| Valid | 60-89 | Probably fine but has some risk signals |
| Risky | 20-59 | Proceed with caution — may bounce |
| Invalid | 0 | Failed a hard check — do not send |
| Unknown | — | Could not determine (DNS timeout, etc.) |
Credits
- Quick mode: 1 credit per email verified
- Deep mode: 2 credits per email verified
- Every TrekMail plan includes free monthly credits (Nano: 10, Starter: 100, Pro: 300, Agency: 1,000)
- Purchase additional credits in bulk when you need more
- Monthly credits reset on your billing date; purchased credits never expire
Getting started
- Go to Email Verifier in the sidebar
- Paste emails or upload a CSV/XLSX file
- Review results and download a filtered CSV
See Email Verifier — Getting Started for a step-by-step guide.
Related articles
Jump to nearby guides that continue the workflow.