Statistic helpers

For full details and examples, run Get-Help Export-MboxStatistics -Detailed or Get-Help Get-MboxStatistics -Detailed. CSV export commands in this section finish with a success message that includes the generated CSV path, and they do not echo the path as a second pipeline line.

Export-MboxStatistics

Export mailbox statistics (size, quotas, archive info) either to CSV (all mailboxes) or as objects (single mailbox). The CSV export can flush in batches, resume from the latest matching CSV, or resume from a specific file.

Syntax

Export-MboxStatistics [-UserPrincipalName <String>] [-CsvFolder <String>] [-CsvPath <String>] [-Round] [-BatchSize <Int>] [-Resume] [-MaxConsecutiveErrors <Int>]

Parameter	Type	Description	Required	Default
UserPrincipalName	String	Optional single mailbox identity; when omitted, all mailboxes are exported to CSV.	No	-
CsvFolder	String	Output folder (for all-mailbox export).	No	Current directory
CsvPath	String	Optional CSV file to resume. When omitted with -Resume, the most recent matching CSV in CsvFolder is used.	No	-
Round	Switch	Round quota values up to the nearest integer GB.	No	False
BatchSize	Int	Flush to CSV every N mailboxes.	No	25
Resume	Switch	Resume from an existing mailbox statistics CSV instead of starting a new report.	No	False
MaxConsecutiveErrors	Int	Stop after this many mailbox-level failures in a row.	No	5

Examples

# Export every mailbox to CSV (batched writes)
Export-MboxStatistics -CsvFolder 'C:\Temp\Reports' -Round

# Resume from the latest matching CSV in the folder
Export-MboxStatistics -CsvFolder 'C:\Temp\Reports' -Resume

# Resume from a specific CSV file
Export-MboxStatistics -CsvPath 'C:\Temp\Reports\20260414_M365-MailboxStatistics.csv' -Resume

# Inspect a single mailbox as objects
Export-MboxStatistics -UserPrincipalName 'user@contoso.com'

Export-MboxDeletedItemSize

Export deleted item store usage for user mailboxes. The report is exported to CSV by default and can be flushed in batches or resumed from a previous CSV. The CSV includes UserPrincipalName so resume can skip already exported mailboxes safely.

Syntax

Export-MboxDeletedItemSize [[-UserPrincipalName] <String[]>] [-CsvFolder <String>] [-Csv] [-BatchSize <Int32>] [-Resume] [-CsvPath <String>] [-MaxConsecutiveErrors <Int32>]

Parameter	Type	Description	Required	Default
UserPrincipalName (User, Identity, Mailbox, SourceMailbox)	String[]	Optional mailbox identity or identities. When omitted, all user mailboxes are scanned. Pipeline accepted.	No	-
CsvFolder	String	Destination folder for the CSV file.	No	Current directory
Csv	Boolean	Export the report to CSV. Use -Csv:$false to return objects instead.	No	True
BatchSize	Int	Flush partial results every N processed mailboxes.	No	25
Resume	Switch	Resume from the latest matching CSV in CsvFolder or from CsvPath.	No	False
CsvPath	String	Explicit CSV file to resume.	No	-
MaxConsecutiveErrors	Int	Stop after this many consecutive mailbox-level failures.	No	5

Examples

# Export all user mailboxes to CSV
Export-MboxDeletedItemSize

# Export a subset of mailboxes to a custom folder
'user1@contoso.com','user2@contoso.com' | Export-MboxDeletedItemSize -CsvFolder 'C:\Temp\Reports'

# Resume from the latest matching CSV in the folder
Export-MboxDeletedItemSize -CsvFolder 'C:\Temp\Reports' -Resume

Get-MboxStatistics

Return a simplified mailbox statistics view as objects.

Syntax

Get-MboxStatistics [-UserPrincipalName <String>] [-IncludeArchive] [-IncludeMessageActivity] [-Round]

Parameter	Type	Description	Required	Default
UserPrincipalName	String	Optional mailbox identity (also from pipeline, including multiple values); when omitted, all mailboxes are returned.	No	-
IncludeArchive	Switch	Include archive size, quota, and usage info when archive is enabled.	No	False
IncludeMessageActivity	Switch	Include message activity fields (LastReceived, LastSent, OldestItemReceivedDate, OldestItemFolderPath).	No	False
Round	Switch	Round quota values up to the nearest integer GB.	No	True

Output (main fields)

• DisplayName
• UserPrincipalName
• PrimarySmtpAddress
• MailboxTypeDetail
• ArchiveEnabled
• MailboxSizeGB
• ItemCount
• MailboxCreated
• LastLogonTime
• WarningQuotaGB
• ProhibitSendQuotaGB
• PercentUsed
• LastReceived (only with -IncludeMessageActivity)
• LastSent (only with -IncludeMessageActivity)
• OldestItemReceivedDate (only with -IncludeMessageActivity)
• OldestItemFolderPath (only with -IncludeMessageActivity)
• ArchiveSizeGB (only with -IncludeArchive)
• ArchiveQuotaGB (only with -IncludeArchive)
• ArchivePercentUsed (only with -IncludeArchive)

Examples

# Quick glance at a single mailbox
Get-MboxStatistics -UserPrincipalName 'user@contoso.com'

# Include archive data
Get-MboxStatistics -UserPrincipalName 'user@contoso.com' -IncludeArchive

# Include message activity (latest trace + oldest item details)
Get-MboxStatistics -UserPrincipalName 'user@contoso.com' -IncludeMessageActivity

# Multiple mailboxes from pipeline
'user1@contoso.com','user2@contoso.com','user3@contoso.com' | Get-MboxStatistics -IncludeArchive

# All mailboxes (may take a while due to message trace queries)
Get-MboxStatistics -IncludeMessageActivity