Use case · SimpleVerifier Team
Real-time email verification for lead forms
Verify a lead form's email field when the form is submitted, through the API from your backend or a Zapier or Make step, and store the status with the lead. Ask the visitor to retype an invalid address while they are still on the page, accept risky ones, and send only valid leads into instant follow-up.
A lead form has one moment when a bad address can be fixed: before the visitor leaves the page. After that, a typo is a lost lead. This page covers the implementation; SaaS signups covers the account-creation case.
What a lead form gets wrong
Typos are only fixable on the page
Once the visitor has gone, there is no way to reach them to ask. An inline error that says the address cannot receive mail gets most typos corrected.
Regex is both too lax and too strict
A pattern accepts addresses on domains with no mail server and sometimes rejects legitimate ones. Keep a light browser check, and do the real check on the server. Email validation regex covers the limits.
API keys in the browser
Calling a verification API directly from front-end code exposes your key. Route the call through your own endpoint or an automation step.
Phone fields need the same care
If the form asks for a phone number, validate it on the same submit: the phone endpoint returns valid or invalid, E.164 and type.
Implementing it
Post the form to your server or a webhook
Your backend, a serverless function, or a Zapier/Make webhook. See verifying leads with Zapier.
Call /api/v1/verify, and /api/v1/phone if there's a phone field
Both are in the API reference; SDKs wrap them for Node.js and Python.
Return a field error for invalid results
'This address can't receive email, please check it' works better than a generic error. Don't block on risky.
Save status, reason and E.164 on the lead
Map them to fields in your CRM so routing rules and follow-up can use them.
Fail open on timeouts
If the check takes longer than your form can wait, accept the lead and verify it in the background.
Form responses by result
| Result | What to do | Why |
|---|---|---|
| valid | Accept; instant follow-up | Confirmed mailbox. |
| risky | Accept; normal follow-up | Catch-all, role or unconfirmed. Not a reason to turn a lead away. |
| invalid · Disposable address | Ask for another address | Throwaway inbox. |
| invalid · other reasons | Show 'please check your email' | Usually a typo the visitor can fix. |
| phone invalid | Ask to check the number | Doesn't fit its country's numbering plan. |
Email and phone checks on submit
curl "https://simpleverifier.com/api/v1/verify?email=jane@company.com" \
-H "Authorization: Bearer $SIMPLEVERIFIER_KEY"
curl "https://simpleverifier.com/api/v1/phone?phone=07911%20123456&country=GB" \
-H "Authorization: Bearer $SIMPLEVERIFIER_KEY"Full request and response details are in the API reference.
Common questions
- Should I verify email on the client or the server?
- On the server. A light syntax check in the browser is fine, but the API call needs your key, which must stay private.
- Can I verify form leads without writing code?
- Yes. A Zapier or Make step can call the API between the form and your CRM and write the status to the lead.
- Should risky leads be rejected?
- No. Risky usually means a company domain that accepts every address. Accept the lead and let your follow-up show whether it is real.
Get an API key
Pro is $29.99 a month with no cap on verifications: CSV uploads, the API, the Google Sheets add-on and the email finder are all included. Cancel any time.
See plans and pricing