A forensic investigator needs to identify where email messages are stored on a Microsoft Exchange server. Which file extension is used by Exchange…

Microsoft Exchange Server uses the Extensible Storage Engine (ESE), also known as the Joint Engine Technology (JET) Blue, as its underlying database engine. The primary database file that stores all user mailbox data—including emails, calendar items, and contacts—is the mailbox database file, which has the .edb extension. Forensic analysis of an Exchange server environment critically involves the examination of these .edb files to recover and analyze user communications and activities.

B. .nsf: This file extension is for the Notes Storage Facility, the database format used by HCL Domino/Notes (formerly IBM/Lotus Domino/Notes), not Microsoft Exchange.

C. .mail: This is a generic extension and not the specific format for an entire Microsoft Exchange mailbox database, which contains multiple mailboxes and items.

D. .db: While a generic extension for database files (e.g., SQLite), it is not the specific extension used by Microsoft Exchange, which uses .edb for its ESE database.

1. Microsoft Corporation. (2023). Manage mailbox databases in Exchange Server. Microsoft Learn. Retrieved from https://learn.microsoft.com/en-us/exchange/architecture/mailbox-servers/manage-mailbox-databases?view=exchserver-2019.

Reference Point: In the section "Mailbox database files," the documentation explicitly states, "The mailbox database files have an .edb extension."

2. Carvey, H. (2014). Windows Forensic Analysis Toolkit, Fourth Edition. Syngress.

Reference Point: Chapter 10, "Email Analysis," discusses the structure of Exchange Server data, identifying the .edb (Extensible Storage Engine Database) file as the primary repository for mailboxes.

3. Nelson, B., Phillips, A., & Steuart, C. (2015). Guide to Computer Forensics and Investigations (5th ed.). Cengage Learning.

Reference Point: Chapter 10, "E-mail and Social Media Investigations," Section "Examining E-mail Messages," describes Microsoft Exchange server artifacts, specifying that mailbox data is stored in .edb database files.