Email IP Leak Checker - KingSMTP

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Is your real IP hiding in your email headers?

Paste any email's headers and instantly map every IP address in the delivery path — each one labelled by type, in the order it handled your message. See exactly which addresses appear in your mail.

No data leaves your browser<br>Instant results<br>Works with any provider

Email IP Leak Checker

Open the email you want to inspect, view its raw headers, and paste them below.

Email Headers<br>In Gmail: open the email → ⋮ → Show original → copy all

Analyze Headers

Load sample

Parsed locally — nothing is uploaded

Delivery path · oldest hop first

What the labels mean

Send through KingSMTP →<br>Dedicated relay IPs · No KYC · Crypto accepted

The basics

What is an email IP leak?

Every email you send carries a hidden trail of Received headers — one for each server that touched the message. Those lines record IP addresses, and depending on how you send, one of them can be yours.

When you send mail directly from a desktop client, a home server, or a misconfigured app, the very first Received header often contains your real public IP address. Anyone who opens the full headers can see it, look it up, and learn your hosting provider, rough location, or even that the message came from a residential connection.

Worse, some setups expose a private or internal IP — addresses like 192.168.x.x or 10.x.x.x. These reveal the internal structure of your network and are a clear sign that mail is being injected without a proper relay in front of it.

This tool reads those headers, lists every IP in order, classifies each one as public or private, and tells you which address originated the message — so you know exactly what your recipients can see.

Your public IP

Exposes your server or home connection — its provider, network, and approximate location are all one lookup away.

Private network IPs

Internal addresses that should never leave your LAN. When they appear in headers, they map out your infrastructure.

The fix: a relay

Send through a relay and your mail leaves from clean, dedicated IPs. Your own server IP never reaches the headers.

Step by step

How to find your email headers

Headers aren't shown by default — you have to open the raw source of a message. Here's how in the three most common clients.

Gmail<br>Outlook<br>Apple Mail

Open the email you want to check.

Click the three-dot menu ⋮ in the top-right of the message.

Choose Show original.

Select everything on the page and copy it, then paste it into the tool above.

Double-click the email to open it in its own window.

Go to File → Properties.

Copy the text in the Internet headers box.

Paste it into the tool above and click Analyze.

Open the message in Apple Mail.

Go to View → Message → All Headers (or press ⌘⇧H).

Select the header block and copy it.

Paste it into the tool above.

FAQ

Questions about email IP leaks

Can someone see my IP address from an email I sent?<br>Yes. Every email carries Received headers that record each server in the delivery path, including the address that first injected the message. If you send directly from a desktop mail client or a misconfigured server, your real public IP — and sometimes your private network IP — is visible to anyone who reads the full headers.

How do I find the IP address in an email header?<br>Open the email and view its raw source (in Gmail: the three-dot menu, then Show original). Look at the Received lines. The bottom-most Received line is the origin of the message and usually contains the sending IP address in square brackets. The checker above does this automatically for you.

Does Gmail show my IP when I send email?<br>When you send from the Gmail web interface, Google relays the message from its own servers, so your personal IP is usually hidden. But if you use Gmail with an external SMTP client, a third-party app, or your own mail server, your originating IP can still appear in the headers. The only way to be sure is to check the headers of a message you actually sent.

What's the difference between a public and a private IP leak?<br>A public IP leak exposes the internet-facing address your mail came from — useful to anyone profiling the sender. A private IP leak exposes internal addresses (like 192.168.x.x or 10.x.x.x) that should never leave your network; these reveal how your infrastructure is laid out and almost always mean mail is being sent without a proper relay in front of it.

How do I hide my IP address when sending email?<br>Send through a transactional SMTP relay instead of sending directly. The relay accepts your message over an authenticated connection and re-sends it from its own clean, dedicated IPs, so your server or home IP never appears in the public headers. KingSMTP does exactly this — and accepts crypto with no KYC for full privacy.

Is this checker free, and does it store my headers?<br>It's completely free with no signup. Everything is parsed...