Retrieving email headers

Find out how to view headers in your email client

Last updated 19th November 2021


The role of an email header is to trace the path taken by an email on the network, from the sender to the recipient.
You can use it to identify malicious emails or detect slow reception.

Every email you receive has a header but it is not displayed by default when you view your email. You can however retrieve the header from your email client or webmail.

You can also export the entire email as a .eml file. This file may be requested to scan a malicious email you received.
To retrieve a .eml file, go to the Webmail section below.

This guide explains how to retrieve an email header from your email client.



Understanding the content of a header

The header is composed of several elements indicating the path of the email. These are arranged in reverse chronological order, from the newest to the oldest entry, followed by additional information.
Below is a non-exhaustive list of the elements that can make up a header, along with their meaning.

  • The Received field is present in the header each time the email is sent to an outgoing server (SMTP). The host name of the server is usually found with its IP address and a timestamp. The Received fields are sorted from the most recent pass to the oldest pass on a server:

    Received: from (unknown [])
        by (Postfix) with ESMTPS id 448F4140309
        for <> ;Wed, 30 Jun 2021 13:12:40 +0000 (UTC)
    Here the email was sent from server to server on 30 June 2021 at 13:12:40 (time zone UTC).

  • The Return-Path field corresponds to the return address when the message failed to be sent. The return address is usually the one that sent the email.

    Return-Path: <>

  • The From field indicates the email sender address and display name.

    From: John <>

  • The To field indicates the email recipient address and display name.

    To: Robert <>

  • The Subject field is the subject of the email.

    Subject: Hello my friend

  • The Message-ID field designates the unique identifier of the email and ends with the name of the outgoing server (after the "@").

    Message-ID: <>

  • The Received-SPF field displays the result of the SPF check performed on the sender's domain name. You can use the client-ip argument to find the IP address of the server that sent the email.

    Received-SPF: Pass (mailfrom) identity=mailfrom; client-ip=;;;

  • The X- fields are custom fields. They serve as complements to the standard fields. They are implemented by the servers that the emails pass through.

    X-OVH-Remote: (
    X-Ovh-Tracer-Id: 1234567891011121314

Recovering a header from an email client

Microsoft Outlook

To read the header, open the email of your choice in a separate window by double-clicking it in the list.

In the new window, click File in the top left-hand corner.


Then select Info on the left, and click Properties.


The full email header appears in the lower box. You can select the entire text and copy it to a file.


Mozilla Thunderbird

To display the header, select the email you want, then press Ctrl and U at the same time.


The full email header appears in a separate window, you can select the entire text and copy it to a file.

macOS email

To display the header, select the email you want and open View in the top menu bar. Then go to Message and click All Headers.


The full email header appears in a separate window. You can select the entire text and copy it to a file.

Retrieving a header on webmail

Outlook Web Application (OWA)

Retrieving the header

To display the header, select the email you want and click on the arrow to the right of Reply All. Click on View Message Details. A new window will open with the full email header, allowing you to download it.


Also see our video tutorial:

Retrieving the .eml file

To download the .eml file, click on (+) New to create a new email.

Select the email you want to extract, then drag and drop it into the content of the new email.

Click the down arrow next to the attachment you just created, and then click Download to save the file to your device.


Retrieving a header on external email clients


To retrieve the header, select the email concerned, then click the 3 vertical dots on the right. Click on Show original to open a new window with the full email header, which also allows you to download it in .eml format.


To view the header in the webmail interface, see the Outlook Web Application topic in this guide.

Go further

Email FAQ

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