You can search for such events with the Search-UnifiedAuditLog cmdlet. The customer asked for a ready to use reports (CSV), which I created for them.
I had to do several exports for different mailboxes, so I decided to create myself the Search-MailboxItemDeletion cmdlet:
function Search-MailboxItemDeletion
{
<#
.SYNOPSIS
Search for deletions in mailboxes
.DESCRIPTION
Search for deletions in mailboxes, single or all
.PARAMETER Days
Day (period) to search, max. 90 (or 30, based on your O365/M365 license).
The default is 7 (for the last 7 days)
Minimum is 1, maximum is 90. This will be checked
.PARAMETER Mailbox
Mailbox Address
e.g. [email protected]
.PARAMETER All
Get all deletes, for all mailboxes
.EXAMPLE
PS C:\> Search-MailboxItemDeletion -All
Get all deletes, for all mailboxes
.EXAMPLE
PS C:\> Search-MailboxItemDeletion -Days 2 | Where-Object -FilterScript { $_.Folder -ne 'Deleted Items' }
Get all deletes of the last 2 days, for all mailboxes, but we exclude one Folder.
.EXAMPLE
PS C:\> Search-MailboxItemDeletion -Days 7 | Where-Object -FilterScript { $_.Folder -ne 'Deleted Items' }
Get all deletes of the last 7 days, for all mailboxes, but we exclude one Folder.
.EXAMPLE
PS C:\> Search-MailboxItemDeletion -Days 30 | Where-Object -FilterScript { ($_.Folder -ne 'Drafts') -and ($_.Action -ne 'SoftDelete') }
Get all deletes of the last 30 days, for all mailboxes, but we exclude one Folder and the 'SoftDelete' action
.EXAMPLE
PS C:\> Search-MailboxItemDeletion -Days 21 -All
Get all deletes for the last 21 days, for all mailboxes
.EXAMPLE
PS C:\> Search-MailboxItemDeletion -All | Out-GridView
Search for Deletions in all mailboxes and open the result in the GridView (e.g. for filtering)
.EXAMPLE
PS C:\> Search-MailboxItemDeletion -Mailbox '[email protected]'
Search for Deletions in the mailbox '[email protected]'
.EXAMPLE
PS C:\> Search-MailboxItemDeletion -Mailbox '[email protected]' | Select-Object -Property 'Timestamp', 'Action', 'Status' , 'User', 'Mailbox', 'Subject', 'Folder', 'Client', 'ClientIP'
Search for Deletions in the mailbox '[email protected]', and get a few more properties (e.g. Status, Client, and ClientIP).
Might be handy to see from where it was triggered and what client was used.
.EXAMPLE
PS C:\> Search-MailboxItemDeletion -Mailbox '[email protected]' | Export-CSV -NoTypeInformation -Path c:\scripts\PowerShell\exports\ExchangeOnlineMailboxDeletes.csv
Search for Deletions in the mailbox '[email protected]' and export the result into a CSV File (e.g. for a basic reporting or further investigation in Excel)
.OUTPUTS
array
.LINK
Search-UnifiedAuditLog
.NOTES
For now, the following properties are supported:
Action string
AppId string
Client string
ClientIP string
External bool
ExternalAccess bool
Folder string
InternalLogonType int
InternetMessageId string
LogonType int
Mailbox string
MailboxGuid string
MessageId string
OrganizationId string
OrganizationName string
OriginatingServer string
SessionId string
Status string
Subject string
TimeStamp string
User string
By default, the following properties are returned (all others can be selected):
TimeStamp string
Action string
User string
Mailbox string
Subject string
Folder string
Requirements:
PowerShell or Windows PowerShell
Exchange Online connection (e.g. the installed Module and you need to be connected with a user that has rights to use Search-UnifiedAuditLog)
A future version might support Wildcards in the Mailbox parameter and/or multi Mailbox searches.
Workaround: use Where-Object with a powerful FilterScript!
#>
[CmdletBinding(DefaultParameterSetName = 'All',
ConfirmImpact = 'None')]
[OutputType([array])]
param
(
[Parameter(ValueFromPipeline,
ValueFromPipelineByPropertyName)]
[ValidateNotNullOrEmpty()]
[ValidateNotNull()]
[int]
$Days = 7,
[Parameter(ParameterSetName = 'Single', HelpMessage = 'Mailbox Address e.g. [email protected]',
Mandatory,
ValueFromPipeline,
ValueFromPipelineByPropertyName)]
[ValidateNotNullOrEmpty()]
[ValidateNotNull()]
[Alias('MailboxName', 'MailboxAddress')]
[string]
$Mailbox,
[Parameter(ParameterSetName = 'All')]
[switch]
$All
)
begin
{
# Garbage Collection
[GC]::Collect()
# Cleanup
$Records = $null
# TimeSpan
$StartDate = (Get-Date).AddDays(-$Days)
# Now
$EndDate = (Get-Date)
#region HelperFunctions
function Get-StandardMembersFromPSObject
{
<#
.SYNOPSIS
Filter the given properties from a given Object
.DESCRIPTION
Filter the given properties from a given Object
.PARAMETER InputObject
The input object, must be a psobject.
.PARAMETER Properties
The properties to select from the given input object.
Multiple values needs to separated by a comma.
.EXAMPLE
Get-StandardMembersFromPSObject -InputObject Value -Properties Value
Describe what this call does
.OUTPUTS
psobject
.NOTES
Just an internal Helper function
.LINK
https://learn-powershell.net/2013/08/03/quick-hits-set-the-default-property-display-in-powershell-on-custom-objects/
.LINK
http://stackoverflow.com/questions/1369542/can-you-set-an-objects-defaultdisplaypropertyset-in-a-powershell-v2-script/1891215#1891215
.INPUTS
psobject, string
#>
[CmdletBinding(ConfirmImpact = 'None')]
[OutputType([psobject])]
param
(
[Parameter(Mandatory,
ValueFromPipeline,
ValueFromPipelineByPropertyName,
HelpMessage = 'The input object, must be a psobject.')]
[ValidateNotNull()]
[ValidateNotNullOrEmpty()]
[psobject]
$InputObject,
[Parameter(ValueFromPipeline,
ValueFromPipelineByPropertyName)]
[ValidateNotNull()]
[ValidateNotNullOrEmpty()]
[Alias('DefaultProperties')]
[string[]]
$Properties = $null
)
process
{
try
{
$defaultDisplayPropertySet = (New-Object -TypeName System.Management.Automation.PSPropertySet -ArgumentList ('DefaultDisplayPropertySet', [string[]]$Properties))
$PSStandardMembers = ([Management.Automation.PSMemberInfo[]]@($defaultDisplayPropertySet))
$InputObject | Add-Member -MemberType MemberSet -Name PSStandardMembers -Value $PSStandardMembers -Force
}
catch
{
#region ErrorHandler
# get error record
[Management.Automation.ErrorRecord]$e = $_
# retrieve information about runtime error
$info = [PSCustomObject]@{
Exception = $e.Exception.Message
Reason = $e.CategoryInfo.Reason
Target = $e.CategoryInfo.TargetName
Script = $e.InvocationInfo.ScriptName
Line = $e.InvocationInfo.ScriptLineNumber
Column = $e.InvocationInfo.OffsetInLine
}
# output information. Post-process collected info, and log info (optional)
$info | Out-String | Write-Verbose
#endregion ErrorHandler
}
}
}
#endregion HelperFunctions
}
process
{
# Get the UnifiedAuditLog Data, with the delete operations
$Records = (Search-UnifiedAuditLog -StartDate $StartDate -EndDate $EndDate -Operations 'HardDelete', 'SoftDelete')
# Do we have a result
if ($Records)
{
Write-Verbose -Message ('Processing ' + $Records.Count + ' audit records...')
# Create a new Object
$Report = [Collections.Generic.List[Object]]::new()
foreach ($Rec in $Records)
{
$AuditData = (ConvertFrom-Json -InputObject $Rec.Auditdata)
if ($AuditData.ResultStatus -eq 'PartiallySucceeded')
{
$MessageSubject = '# Not fully deleted by' + $AuditData.ClientInfoString + ' #'
}
else
{
$MessageSubject = ($AuditData.AffectedItems.Subject -split '\n')[0]
}
$ReportLine = [PSCustomObject] @{
TimeStamp = (Get-Date -Date ($AuditData.CreationTime) -Format g)
User = $AuditData.UserId
Action = $AuditData.Operation
Status = $AuditData.ResultStatus
Mailbox = $AuditData.MailboxOwnerUPN
MailboxGuid = $AuditData.MailboxGuid
Subject = $MessageSubject
MessageId = ($AuditData.AffectedItems.Id -split '\n')[0]
InternetMessageId = ($AuditData.AffectedItems.InternetMessageId -split '\n')[0]
Folder = $AuditData.Folder.Path.Split('\')[1]
Client = $AuditData.ClientInfoString
AppId = $AuditData.AppId
ClientIP = $AuditData.ClientIP
External = $AuditData.ExternalAccess
SessionId = $AuditData.SessionId
ExternalAccess = $AuditData.ExternalAccess
InternalLogonType = $AuditData.InternalLogonType
LogonType = $AuditData.LogonType
OrganizationName = $AuditData.OrganizationName
OrganizationId = $AuditData.OrganizationId
OriginatingServer = $AuditData.OriginatingServer
}
# Define the default properties and support Select-Object
Get-StandardMembersFromPSObject -InputObject $ReportLine -Properties 'Timestamp', 'Action', 'User', 'Mailbox', 'Subject', 'Folder'
# Add to the reporting
$Report.Add($ReportLine)
}
$Records = $null
}
else
{
Write-Output -InputObject 'No deletion records found.'
break
}
# Create a new array object
$Output = @()
# Single or all ?
switch ($PsCmdlet.ParameterSetName)
{
'Single'
{
$Output = ($Report | Where-Object -FilterScript {
# You might want to tweak the filter to support Wildcards or more the one mailbox
$_.Mailbox -eq $Mailbox
})
}
'All'
{
$Output = ($Report | Sort-Object -Property Mailbox)
}
}
# Cleanup
$Report = $null
}
end
{
# Just dump the result to the terminal
$Output
# Cleanup
$Output = $null
# Garbage Collection
[GC]::Collect()
}
}
#region LICENSE
<#
BSD 3-Clause License
Copyright (c) 2021, enabling Technology
All rights reserved.
Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
3. Neither the name of the copyright holder nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#>
#endregion LICENSE
#region DISCLAIMER
<#
DISCLAIMER:
- Use at your own risk, etc.
- This is open-source software, if you find an issue try to fix it yourself. There is no support and/or warranty in any kind
- This is a third-party Software
- The developer of this Software is NOT sponsored by or affiliated with Microsoft Corp (MSFT) or any of its subsidiaries in any way
- The Software is not supported by Microsoft Corp (MSFT)
- By using the Software, you agree to the License, Terms, and any Conditions declared and described above
- If you disagree with any of the terms, and any conditions declared: Just delete it and build your own solution
#>
#endregion DISCLAIMER
There is also a Gistfor the Search-MailboxItemDeletion cmdlet available and it is part of my PowerShell Repository.
Please see the examples of the Search-MailboxItemDeletion cmdlet.
There are a few requirements:
- PowerShell or Windows PowerShell
- The Exchange Online Management Module (Install its with
Install-Module -Name ExchangeOnlineManagementfrom the PowerShell Gallery) - A connection to Exchange Online (Use
Connect-ExchangeOnlinefor that) - The user needs the permission to use the Search-UnifiedAuditLog cmdlet
- Mailbox auditing needs to be enabled (what I recommend anyway!)
The script will not check for any of the requirements above!