In many organizations the Exchange Server administrator will encounter a situation where there is a need to determine who took action on an item in a mailbox. This will most often be about actions taken by delegates of a person’s mailbox, or people who use a shared mailbox.
For example:
- An email message from a customer was never responded to, and the manager of the customer service team wants to know which person in the team move or deleted the message from the shared mailbox
- Information sent to an executive via email has leaked, and there is an investigation into which of the executive’s delegates read the email message
Note that in these situations it is assumed that delegates or a team of people already have full access to the mailbox, or read-only access to the mailbox. Based on that assumption the focus is now on which of those people took action on specific mail items.
Exchange Server 2013 can log access to mailboxes by the owner, delegates, and administrators, using a feature called mailbox audit logging.
How Mailbox Audit Logging Works
When mailbox audit logging is enabled for a mailbox, audit log entries are stored in the Recoverable Items folder of the mailbox, which is not visible to the mailbox user via Outlook or other client interfaces.
Log entries are written for actions taken by the mailbox owner, delegates, or by administrators, depending on the audit logging configuration applied to the mailbox. The mailbox audit log entries are then retained for a configurable period of time.
Mailbox audit logging has the following default configuration in Exchange Server 2013:
- Mailbox audit logging is disabled
- Audit log entries are retained for 90 days
- No owner actions are logged
- Some delegate and administrator actions are logged
A default mailbox audit logging configuration for an Exchange 2013 mailbox looks like this:
[PS] C:\>Get-Mailbox alan.reid | fl *audit*
AuditEnabled : False
AuditLogAgeLimit : 90.00:00:00
AuditAdmin : {Update, Move, MoveToDeletedItems, SoftDelete, HardDelete, FolderBind, SendAs, SendOnBehalf, Create}
AuditDelegate : {Update, SoftDelete, HardDelete, SendAs, Create}
AuditOwner : {}
Note: The AuditAdmin settings refer to access via mechanisms such as eDiscovery searches, mailbox import/export operations, or tools such as MFCMAPI. If an administrator is granted permission to a mailbox and accesses it then those actions will be logged according to the AuditDelegate settings.
Enabling/Disabling Mailbox Audit Logging
For mailboxes in your organization that you wish to enable audit logging on you can do so using the Set-Mailbox cmdlet.
[PS] C:\>Set-Mailbox alan.reid -AuditEnabled $true
Typical candidates for mailbox audit logging are executives or VIPs who handle sensitive information, and who have delegates, or shared mailboxes used by teams of people.
In some organizations it may be preferable to enable mailbox audit logging for large numbers of mailbox users, or perhaps even all mailbox users. You can pipe the output of any Get-Mailbox query into Set-Mailbox to enable mailbox audit logging.
[PS] C:\>Get-Mailbox -ResultSize Unlimited | Set-Mailbox -AuditEnabled:$true
For more information see:
Impact of Audit Logging on Mailbox Size
Mailbox audit log data is stored in a folder named Audits under the Recoverable Items folder of the mailbox, so it is hidden from the user. The default retention is 90 days, and some administrators may be concerned about the storage overhead for all of that audit logging data.
For more information on this see How Much Database Storage Does Mailbox Audit Logging Consume?
Searching Mailbox Audit Logs
In an upcoming article I will demonstrate some methods for searching and using the mailbox audit logging data.
This article Using Exchange Server 2013 Mailbox Audit Logging is © 2014 ExchangeServerPro.com
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