Mailbox Configuration¶

Connect-ExchangeOnline -UserPrincipalName admin@domain.com

# Verify audit is enabled for a user
Get-Mailbox -Identity user@domain.com | Select-Object AuditEnabled, AuditOwner, AuditDelegate, AuditAdmin

# Enable auditing on all mailboxes (should already be on)
Get-Mailbox -ResultSize Unlimited |
    Where-Object { $_.AuditEnabled -eq $false } |
    Set-Mailbox -AuditEnabled $true

# Recommended audit actions to capture
Set-Mailbox -Identity user@domain.com `
    -AuditOwner @{Add="MailboxLogin","HardDelete","SoftDelete","Update","Move","MoveToDeletedItems","SendAs","SendOnBehalf"} `
    -AuditDelegate @{Add="HardDelete","SoftDelete","SendAs","SendOnBehalf","Update","Move"} `
    -AuditAdmin @{Add="HardDelete","MessageBind","SendAs","SendOnBehalf"}

# Find mailboxes with forwarding configured
Get-Mailbox -ResultSize Unlimited |
    Where-Object { $_.ForwardingAddress -ne $null -or $_.ForwardingSmtpAddress -ne $null } |
    Select-Object DisplayName, UserPrincipalName, ForwardingAddress, ForwardingSmtpAddress, DeliverToMailboxAndForward

# Find inbox rules that forward externally
Get-Mailbox -ResultSize Unlimited | ForEach-Object {
    Get-InboxRule -Mailbox $_.UserPrincipalName -ErrorAction SilentlyContinue |
        Where-Object { $_.ForwardTo -ne $null -or $_.RedirectTo -ne $null -or $_.ForwardAsAttachmentTo -ne $null } |
        Select-Object @{N="Mailbox";E={$_.MailboxOwnerID}}, Name, ForwardTo, RedirectTo
}

# Enable litigation hold with 7-year retention
Set-Mailbox -Identity user@domain.com `
    -LitigationHoldEnabled $true `
    -LitigationHoldDuration 2555 `
    -LitigationHoldOwner "Legal Hold - Case Name"

# Check hold status
Get-Mailbox -Identity user@domain.com |
    Select-Object LitigationHoldEnabled, LitigationHoldDuration, LitigationHoldOwner

# Place all mailboxes on hold (use with caution)
Get-Mailbox -ResultSize Unlimited -Filter {RecipientTypeDetails -eq "UserMailbox"} |
    Set-Mailbox -LitigationHoldEnabled $true

# Get mailbox sizes
Get-Mailbox -ResultSize Unlimited | Get-MailboxStatistics |
    Select-Object DisplayName, TotalItemSize, ItemCount |
    Sort-Object { $_.TotalItemSize.Value.ToBytes() } -Descending |
    Select-Object -First 20

# Check quota settings
Get-Mailbox -Identity user@domain.com |
    Select-Object IssueWarningQuota, ProhibitSendQuota, ProhibitSendReceiveQuota

# Increase mailbox quota for a specific user
Set-Mailbox -Identity user@domain.com `
    -IssueWarningQuota 45GB `
    -ProhibitSendQuota 49GB `
    -ProhibitSendReceiveQuota 50GB `
    -UseDatabaseQuotaDefaults $false

# List existing retention policies
Get-RetentionPolicy | Select-Object Name, RetentionPolicyTagLinks

# Assign a retention policy to a mailbox
Set-Mailbox -Identity user@domain.com -RetentionPolicy "Default MRM Policy"

# Create a shared mailbox
New-Mailbox -Shared -Name "Helpdesk" -DisplayName "IT Helpdesk" -Alias helpdesk

# Grant Full Access and Send As
Add-MailboxPermission -Identity helpdesk -User user@domain.com -AccessRights FullAccess -InheritanceType All
Add-RecipientPermission -Identity helpdesk -Trustee user@domain.com -AccessRights SendAs

# List all shared mailboxes and their members
Get-Mailbox -RecipientTypeDetails SharedMailbox | ForEach-Object {
    $mb = $_
    $members = Get-MailboxPermission $mb.Identity |
        Where-Object { $_.User -notlike "NT AUTHORITY*" -and $_.IsInherited -eq $false }
    [PSCustomObject]@{
        SharedMailbox = $mb.DisplayName
        Members = ($members.User -join ", ")
    }
}

# Disable Focused Inbox organisation-wide
Set-OrganizationConfig -FocusedInboxOn $false

# Check current setting
Get-OrganizationConfig | Select-Object FocusedInboxOn