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Dovecot Email Client – Forensic Analysis of File Formats

MailXaminer | September 1st, 2017 | Forensics

 

Different Email client used by all over the world for emails communication and other activities. According to different features, advantages, platform support, work nature, an email client used by people & Organizations. Today, In Digital world, email client application would be more secure so that chance of unauthorized intrusion, financial fraud, a data breach can be prevented. People are using Linux and Unix Operating system and secured email client to store messages safely.

In the list of Linux or Unix supported emails clients, Dovecot is a popular email client supported by also another different platform such as OpenBSD, Mac OS X, NetBSD etc. In this article, we examine facts about the Dovecot Emails client and about its file structure. We also explore the file formats supported by the application and that can help in a forensic investigation as mostly data is digitally stored in file formats.

Analysis of Dovecot Email File Formats

A Dovecot acts as an Open, Free-ware email server supported by Linux/Unix operating system for secure communication. As Server effectively work with existing POP3 & IMAP and also support TLS & SSL protocol. Dovecot uses popular MBOX file format & MAILDIR, DBOX format to store emails and provide different plug-in for mailbox supported tool. User-friendly and smoothly work with a clustered file system. This MBOX file format of Dovecot helps forensic investigator or security agency to find the evidence in email forensics investigation, where crime or fraud has done digitally over the internet through over emails.

Data Storage In Dovecot -MBOX File

A Standard MBOX File format used as Storage file in Dovecot. As MBOX Mailbox format usually stored in default storage path:

storage path

A Message box is a single file holds multiple messages. Where as Maildir format used to store a single message in each file. In Dovecot both file formats help the user to store and search messages quickly. One hand MBOX hold large messages where on other hand Maildir help user to search messages quickly due to the file structure. To specify each message from each other in MBOX File format a “From” line also know as From_-line used but in Dovecot, to identify messages “Content – Length” header is added.

More information of Dovecot MBOX Metadata

UW-IMAP supported header used by Dovecot Email client to store meta-data in MBOX messages. Header information is given below:

mbox metadata of dovecot email

 

DBOX File Format: Third Mailbox file format used in Dovecot know as DBOX format. This file format created by Dovecot itself to improve performance and still used in new V2.0 version. It can be used in two ways, first as storing each message per file like Maildir format and on another way it stores many messages in a single file.
A user can look out the default files folder can be created by Dovecot to store folder of messages.

dovecot email mailbox folder

Role of Mailxaminer in Dovecot Email Forensics

As Mailxaminer Tool can help Cyber & Forensic investigation team effectively inspect each message stored in MBOX file supported by Dovecot client. As investigator can inspect the properties of messages and information stored from different dimension such as Hex view, Message header, Mail information, any HTML information and verified to find evidence in the cyber investigation. Count the no of hops between the source and destination address of the emails.

Conclusion

A Dovecot Email client used for secure communication of information over internet and offer supports to the different platform, protocol, and operating system support. But as the chance of data privacy, email spoofing, malware attacks, phishing increasing and a system is not much advance to stop these kinds of activities completely. To examine these kinds of exercise, Mailxaminer Tool acts as Forensic Expert Tool the field of digital Cyber crime. The tool supports various file format and MBOX is one of them, it offers prominent features that help to find evidence stored in the messages box of the Dovecot Email Client.