Commands › Exchange Online

New-SystemMessage

Exchange Online ExchangeOnlineManagement New-*

Create custom system messages. System messages are delivery status notifications (also known as DSNs, non-delivery reports, NDRs or bounce messages) and quota messages.

Quick start script

# New-SystemMessage — quick start (serv365.ai)
# 1. Connect (app-only shown; interactive: omit the certificate parameters)
Connect-ExchangeOnline -CertificateThumbprint $thumb -AppId $appId -Organization $org

# 2. Capture the current state first — you cannot roll back what you never recorded
$before = Get-SystemMessage
$before | Format-List

# 3. Make the change (dry run first)
New-SystemMessage -DsnCode <EnhancedStatusCode> -Internal <Boolean> -Language <CultureInfo> -WhatIf
New-SystemMessage -DsnCode <EnhancedStatusCode> -Internal <Boolean> -Language <CultureInfo>

# 4. Verify and diff
$after = Get-SystemMessage
Compare-Object ($before | Out-String) ($after | Out-String)

Syntax — 2 parameter sets

Dsn

New-SystemMessage -DsnCode <EnhancedStatusCode> -Internal <Boolean> -Language <CultureInfo> -Text <String>
 [-Confirm]
 [-DomainController <Fqdn>]
 [-WhatIf]
 [<CommonParameters>]

Quota

New-SystemMessage -Language <CultureInfo> -QuotaMessageType <QuotaMessageType> -Text <String>
 [-Confirm]
 [-DomainController <Fqdn>]
 [-WhatIf]
 [<CommonParameters>]

Parameters (8)

Parameter	Type	Required	What it controls
-DsnCode	EnhancedStatusCode	yes	The DsnCode parameter specifies the enhanced status code for the custom system message.
-Internal	Boolean	yes	The Internal parameter specifies whether the system message is displayed to internal or external users. Valid values are:
-Language	CultureInfo	yes	The Language parameter specifies the language of the message (for example, en for English or ja for Japanese). For the list of supported language codes, see [Supported languages for...
-QuotaMessageType	QuotaMessageType	yes	The QuotaMessageType parameter specifies the quota for the custom system message. Valid values are:
-Text	String	yes	The Text parameter specifies the text in the custom system message. The text should explain why the system message was sent, and any actions that the user should take.
-Confirm	SwitchParameter		The Confirm switch specifies whether to show or hide the confirmation prompt. How this switch affects the cmdlet depends on whether the cmdlet requires confirmation before proceeding.
-DomainController	Fqdn		The DomainController parameter specifies the domain controller that's used by this cmdlet to read data from or write data to Active Directory. You identify the domain controller by its fully qualified domain name...
-WhatIf	SwitchParameter		The WhatIf switch shows what the command does without making any changes. You don't need to specify a value with this switch.

Reference facts derived from Microsoft documentation, © Microsoft, licensed CC BY 4.0; restructured with original guidance by serv365.ai.