Verify with EmailShield

EmailShield

Email verification and list cleaning — our sister product · emailshield.co

EmailShield is a list cleaner. Before you send, it checks every address and flags the ones that don’t exist or would bounce. Think of it as spell-check for email addresses. LeadSonar has EmailShield built in: you can verify leads without leaving the app.

Part 1 Infrastructure Maildeck Domains and inboxes you send from Part 2 Sequencer Instantly, PlusVibe… Sends emails and follow-ups Part 3That's us Leads LeadSonar The right people and their emails Part 4 Verification EmailShield Removes bad addresses first

Why verify before you send

When you email an address that doesn’t exist, the email bounces — it comes back undelivered.

Email providers like Google and Microsoft watch your bounce rate. Lots of bounces tells them you’re sending to a list nobody checked, which is what spammers do. Your sender reputation drops, more of your emails land in spam, and in bad cases your domain ends up on a blacklist that many mail servers refuse outright.

The domain is the expensive part to lose: it took weeks of warm-up before it could send. Verifying a list costs far less than replacing a burned domain.

Keep bounces under 5%

If a campaign’s bounce rate goes above about 5%, pause it and clean the list before sending more.

Why a LeadSonar list still needs it

Even a fresh list goes stale: people change jobs every month, and an address that was valid when you exported it can be gone by the time you send. Why fresh leads matter → Verify the week you send, not when you build the list.

How to verify in LeadSonar

1. In Lead Finder → My Leads, select the leads.
2. Click Enrich selected and tick EmailShield verification.
3. Each lead gets an email status: valid (safe to send) or invalid (remove it).

Verification costs 3 credits per lead.

What EmailShield checks

EmailShield asks the recipient’s mail server whether the mailbox exists — without sending an email. It also detects:

• Catch-all domains — servers that accept every address, so a mailbox can’t be confirmed either way. Send to these carefully.
• Disposable addresses — throwaway inboxes.
• Role addresses — shared inboxes like info@ or sales@, which rarely reply to cold email.

For large lists from other sources, bulk uploads, blacklist monitoring and its own API, use EmailShield directly at emailshield.co.