Email header decoder
The fascinating world of email headers!
An email header is a collection of lines of text that precede the body of an email message. Each line is a header field, which provides information about the email, such as the sender, recipient, date, and routing information. Here's a breakdown of the most common email header fields and what they mean:
1. From: The sender's email address.
Example: From: [email protected]
2. To: The recipient's email address.
Example: To: [email protected]
3. Subject: The subject line of the email.
Example: Subject: Meeting Invitation
4. Date: The date and time the email was sent.
Example: Date: Wed, 12 Jan 2022 14:30:00 +0000
5. Message-ID: A unique identifier for the email message.
Example: Message-ID: <[email protected]>
6. In-Reply-To: The message ID of the email that this message is a reply to.
Example: In-Reply-To: <[email protected]>
7. References: A list of message IDs that this message is related to.
Example: References: <[email protected]> <[email protected]>
8. MIME-Version: The version of the Multipurpose Internet Mail Extensions (MIME) standard used to format the email.
Example: MIME-Version: 1.0
9. Content-Type: The type of content in the email body (e.g., text/plain, text/html, application/octet-stream).
Example: Content-Type: text/plain; charset=UTF-8
10. Content-Disposition: The disposition of the email body (e.g., inline, attachment).
Example: Content-Disposition: inline
11. Authentication-Results: Information about the authentication status of the email (e.g., SPF, DKIM, DMARC).
Example: Authentication-Results: spf=pass (mx=include:example.com)
12. Received: A list of servers that received the email, along with the date and time.
Example: Received: from mail.example.com (mail.example.com [192.0.2.1]) by mx.example.net (mx.example.net [192.0.2.2]) with ESMTP id 1234567890; Wed, 12 Jan 2022 14:30:00 +0000
13. X-: Various custom headers added by email clients, servers, or other software.
Example: X-Mailer: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.10.0
To decode an email header, you can use online tools or email clients that support header analysis. Some popular options include:
- Email headers viewer in your email client (e.g., Gmail, Outlook, Thunderbird)
- Online email header analyzers (e.g., Email Header Analyzer, Header Analyzer)
- Command-line tools (e.g.,
mailormuttcommands)
Remember that email headers can be complex and may contain multiple lines of text. When decoding an email header, it's essential to understand the context and the information provided by each header field.