Exchange Mailbox Database
Exchange Mailbox Database is a database used by Microsoft Exchange Server to store user mailboxes and their contents. Mailbox databases contain email messages, attachments, calendar items, contacts, tasks, and other information associated with Exchange mailboxes.
In Exchange Server, a mailbox database is stored as an Exchange Database (.edb) file. A single database can contain multiple mailboxes, while an Exchange organization can use several mailbox databases depending on its size, configuration, and availability requirements.
What Is Stored in an Exchange Mailbox Database?
An Exchange mailbox database provides the main storage location for mailbox data on an Exchange Server. Users access their individual mailboxes, but the underlying information is maintained within one or more mailbox databases.
Mailbox databases are managed at the server level and can be mounted, dismounted, moved, replicated, and backed up. Administrators can also distribute mailboxes between different databases to organize storage and server workloads.
Exchange Mailbox Database Components
EDB Database File. The main Exchange database is stored in an .edb file containing mailbox data for users assigned to that database.
Transaction Logs. Exchange records database changes in transaction log files before those changes are committed to the mailbox database.
User Mailboxes. A mailbox database can store multiple user mailboxes containing messages, attachments, contacts, calendars, and other mailbox items.
Database Copies. Exchange Server can maintain additional copies of a mailbox database on other Mailbox servers within a Database Availability Group.
Exchange Mailbox Database and Mailbox: What Is the Difference?
An Exchange mailbox is the logical storage assigned to an individual user or resource. It contains that user's messages, folders, calendar items, contacts, and other mailbox information.
An Exchange mailbox database is the underlying database that stores multiple mailboxes. In other words, users work with their individual mailboxes, while Exchange Server stores those mailboxes inside one or more mailbox databases.
Mailbox Database Copies and DAG
Microsoft Exchange Server supports mailbox database replication through a Database Availability Group (DAG). A DAG can contain multiple Exchange Mailbox servers and maintain several copies of the same mailbox database.
If the active database or server becomes unavailable, Exchange can activate another database copy. This mechanism is designed for high availability and recovery from server, database, or network failures.
Mailbox database replication and backup serve different purposes. Database copies improve service availability, while an independent backup can provide additional recovery points stored separately from the active Exchange infrastructure.
Exchange Mailbox Database Backup
Backing up an Exchange mailbox database can help preserve mailbox information for recovery after database corruption, hardware failure, accidental data loss, or other incidents affecting the Exchange environment.
Exchange-aware backup applications can work with Microsoft Volume Shadow Copy Service (VSS) to create consistent copies of Exchange databases while the server remains operational. Microsoft also supports VSS-based backup of mailbox database copies within a DAG.
When planning an Exchange database backup strategy, administrators should consider the mailbox database itself, transaction logs, backup frequency, retention periods, storage location, and the required recovery point and recovery time.
For practical information about creating copies of Exchange data with Handy Backup, see Exchange Server Backup.
Exchange Mailbox Database FAQ
What is an Exchange mailbox database?
An Exchange mailbox database is a Microsoft Exchange Server database used to store user mailboxes and their contents. It is stored as an Exchange Database (.edb) file and can contain multiple mailboxes.
What is the difference between an Exchange mailbox and a mailbox database?
A mailbox belongs to an individual user or resource and contains its email and other mailbox items. A mailbox database is the underlying Exchange database that stores multiple mailboxes.
Is an Exchange database copy the same as a backup?
No. Exchange database copies within a Database Availability Group are primarily designed for high availability and failover. A separate backup can provide independent recovery points and can be stored outside the active Exchange environment.
Learn more:
- Outlook Add-ins
"Outlook add-ins - are special extensions for Outlook, which allow you to add extra features to the main program. Interest in the add-ins can be easily…" - Exchange Server Calendar
"Exchange Server Calendar is the calendar functionality built into Microsoft Exchange Server and associated with Exchange mailboxes. It allows users to…" - Exchange Server Message
"The term "Exchange Server message" implies a message processed by Microsoft Exchange Server in accordance with predefined transport and journal rules of…"