How do I Find the ISP of an Email Address?

You can find an email address ISP by viewing the full email headers.

If you are being sent spam or hateful mail, one step you can take is to report the mail sender to their Internet Service Provider (ISP). ISPs have rules about what users can do with their email services, and can sometimes block an account that is breaking those rules. To see the ISP of a sender's email address, you will need to view the email's message headers. Even if the sender has attempted to mask their real address, the real ISP may be listed in the header information. Each email client or browser based mail has a different method of viewing headers.

Instructions

Gmail

1. Log in to your Gmail account and navigate to your Inbox.

2. Open the email message in your Inbox.

3. Click the arrow button located in the top right corner of the window, next to the word "Reply."

4. Choose "Show Original" to display the full email headers in a new window.

5. View the email address ISP in the "Received: from" line in the header. It will usually be followed by a .com, .net or .org extension.

Outlook 2007

1. Launch the Outlook mail client.

2. Double-click a message to open it.

3. Click the "Dialog Box Launcher" icon in the "Options" group. This will display the full email headers in the "Internet headers" box.

4. View the email address ISP in the "Received: from" line in the header. It will usually be followed by a .com, .net or .org extension.

Outlook Express

1. Launch the Outlook Express mail client.

2. Right-click an email from your Inbox window and choose "Properties" from the menu.

3. Navigate to the "Details" tab to see the email headers.

4. View the email address ISP in the "Received: from" line in the header. It will usually be followed by a .com, .net or .org extension.

Thunderbird

1. Launch the Thunderbird mail client.

2. Click on an email in your Inbox list once to highlight it.

3. Click "View" from the top bar, then click "Headers."

4. Choose "All" from the menu. The full email headers will appear in your Inbox window above the original message.

5. View the email address ISP in the "Received: from" line in the header. It will usually be followed by a .com, .net or .org extension.

References

• GMail: Message headers
• The A3C Connection: Reading Email Headers