Solution
Email verification at signup
Validate the address in your signup form before it enters your database. Fewer fake accounts and typos.
- Inline validation
- Less fraud
- Better database from day one
curl -X POST https://propercheck.pl/api/v1/verify \
-H "Authorization: Bearer ev_live_YOUR_KEY" \
-H "Content-Type: application/json" \
-d '{"email":"user@company.com"}'Example API flow
On form submit call POST /api/v1/verify. Invalid → message in the UI. Valid → save the user and optionally double opt-in. Unknown → retry or pending flag in CRM.
- Typical latency 1–5 s — show a spinner in the form.
- 402 when credits run out — monitor balance in the dashboard.
- Separate API keys for staging vs production.
-
Hook on submit
Call POST /verify before saving the user.
-
Show feedback
Invalid → message in the form. Valid → continue the flow.
-
Optional async
For slow MX servers you can verify asynchronously in the background.
“We cleaned 40k leads before a cold email push. Bounce dropped from 9% to under 1% — domain reputation recovered.”
“We upload a CSV from CRM every week. Export with statuses saves hours of manual checking.”
“Trial credits were enough to judge quality. Then we bought a pack for our B2B newsletter.”
Related
Frequently asked questions
Does it slow down signup?
Typically adds 1–3 seconds. You can use async verify after signup with a pending flag.
Can I block only disposable emails at signup?
Yes. In the API you can reject invalid and risky disposable addresses while showing syntax errors to the user immediately.
Does verification replace double opt-in?
No. Verify confirms technical mailbox existence; double opt-in is still recommended for marketing lists.