*This page covers on-premises Exchange instances only. For M365 backup, Bacula Enterprise provides a separate dedicated backup and recovery tool.
As of 2026, 45,754 organizations worldwide run Microsoft Exchange Server on-premises to manage critical business communications, including email, calendars, contacts, and task scheduling. Without regular Exchange backups, organizations risk losing critical mailbox data permanently because a single server crash or a ransomware attack can halt operations indefinitely and expose the business to compliance violations and financial penalties. Email is also the primary attack vector for ransomware, which makes Exchange one of the most targeted systems on a corporate network.
Given that Exchange keeps a portion of its data in memory at all times and only writes it to disk at set intervals, a standard file-based backup tool will miss whatever data is still in memory at the time of execution. In other words, the backup results in an incomplete snapshot that cannot be reliably restored.
To back up Exchange reliably while it is still active, Bacula Enterprise provides two purpose-built backup plugins for two distinct failure scenarios. The VSS Plugin coordinates directly with the Exchange database engine at the full database level. The EWS Plugin coordinates directly with the Exchange database engine at the individual item level.
The Exchange VSS Plugin uses the Windows Volume Shadow Copy Service to capture application-consistent backups at the database level while Exchange remains online, and it is the recommended tool when the whole Exchange deployment has been impacted and the priority becomes getting the full database back online pronto.
