🛠️Should You Build Your Own Email Verifier?
On paper, building your own validator sounds doable:
- Ping the domain
- Check MX records
- Validate syntax
- Maybe add SMTP check?
But in practice, it's a full-blown product:
"Building is just the beginning—maintaining is the real cost."
Let's break down both paths.
💰Option 1: Buy (Using a Provider like Lero)
| Category | Cost |
|---|---|
| API integration | 1–2 hours dev |
| Infra | ❌ (zero infra) |
| Ongoing updates | ❌ (handled by provider) |
| Cost per email | From $0.0003/email |
| SLA | Optional (SaaS-tiered) |
Total upfront cost: ≈ $0
Ongoing cost: Pay-per-use, no lock-in
🧱Option 2: Build Your Own Validator
| Component | Est. Time/Cost |
|---|---|
| SMTP check logic | 30–50 dev hours |
| Disposable domain DB | Need to maintain/update |
| Catch-all detection | Tricky to implement |
| Queueing system (e.g. Celery) | Infra + error handling |
| Concurrency/scalability | Infra engineering time |
| Maintenance/debugging | Recurring weekly hours |
Total upfront cost: ~$3,000–10,000 (dev + infra)
Ongoing: $200–800/month (infra, bugs, updates, IP blocking)
⚠️Hidden Costs Most Teams Miss
SMTP rate-limiting
You'll get blocked by many servers
False positives/negatives
Accuracy drops without feedback loops
Uptime monitoring
This is infra, not just code
Reputation damage
Bad validation = bounce storm
📊Real Example: Buying Saves Thousands
| Metric | Value |
|---|---|
| Emails to validate per month | 50,000 |
| Cost with own infra (AWS + time) | ~$400/mo |
| Cost with Lero | $15.00/month |
💡 If your dev time is worth $50/h, Lero pays for itself in 1 hour.
🤖Why Lero Makes Buying a No-Brainer
50 ms validation
Real-time, usable in signups
97.3% accuracy
Independently verified
From $0.0003/email
Cheaper than infra cost
First 500 validations free
Test without risk
✅Use This Rule of Thumb
| Use Case | Build? | Buy? |
|---|---|---|
| 100K+ monthly emails & in-house dev team | ✅ Maybe | |
| B2B SaaS doing cold outreach | ❌ | ✅✅✅ |
| Lead-gen via ads or newsletter | ❌ | ✅✅✅ |
| Founder solo / indie hacker | ❌ | ✅✅✅ |
| Need to validate now | ❌ | ✅✅✅ |
👇 TL;DR
"If you're not ready to hire a dev and maintain an SMTP pipeline for years, buy it."
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