Received

The Received add-on for Thunderbird displays "Received" headers parsed with a customizable regular expression, allowing for detailed analysis of email routing.

Overview

This add-on clarifies email delivery paths, helping users understand the origins and flow of their emails.

Features

• Core functionality: Displays parts of "Received" message headers that match capturing groups of a regular expression, enabling users to extract specific details.
• Separate matches: Returns individual matches for each "Received" header, facilitating easier analysis and clarity.

Installation

To install the Received add-on, choose one of the following options:

• Download the latest release directly from the Releases page.
• Access versions reviewed by moz://a on the Thunderbird Add-ons page.
• If you need to install a specific commit, download the source code from the repository and create an XPI installer.

Creating an XPI installer

The XPI installation package is essentially a ZIP file with a different extension.

To create it, zip the contents of the add-on's directory (not the add-on directory itself), excluding hidden files and folders that begin with a period. Rename the ZIP file to have an .xpi extension (or simply drag and drop the ZIP into the Add-ons Manager tab).

The ZIP file should maintain the following structure:

received-master.zip
├── chrome/
├── defaults/
├── chrome.manifest
├── install.rdf
└── ... (other files and directories)

And not this structure:

received-master.zip
└── received-master/
    ├── chrome/
    ├── defaults/
    ├── chrome.manifest
    ├── install.rdf
    └── ... (other files and directories)

Usage

• After installation, navigate to the add-on settings to configure the regular expression according to your needs.
• A default regular expression of (.*) will display all "Received" headers. Modify this to display specific parts, such as the originating host.

Example regular expressions

This section presents several regular expressions for parsing "Received" headers in emails. These examples can be customized further based on your needs.

1. Display all "Received" headers:

   (.*)

   Captures all "Received" headers.

2. Identify the originating host:

   ^from (.+?) by mx\.example\.com

   Matches the host in the first "Received" header added by the recipient's SMTP server.

3. Exclude TLS information:

   ^from (.+?)(?: \(using .+ requested\))? by mx\.example\.com

   Similar to the previous example, but omits TLS information if present.

4. Support for multiple mail servers:

   ^from (.+?)(?: \(using .+ requested\))? by (?:mx\.example\.com|mx\.example\.org|[a-z]{3}\d-[0-9a-f]{12}\.qloud-c\.yandex\.net \(mxfront/Yandex\))

   Similar to the previous example, but accommodates accounts configured in Thunderbird on different mail servers, including mx.example.com, mx.example.org, and Yandex.Mail Service.

5. Capture host and timestamp:

   ^from (.+?) by mx\.example\.com.+for.+(; .+)$

   Uses two capturing groups to extract both the host and the timestamp.