Commands › Exchange Online

Set-SystemMessage

Exchange Online ExchangeOnlineManagement Set-*

Modify 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

# Set-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)
Set-SystemMessage -Identity <SystemMessageIdParameter> -WhatIf
Set-SystemMessage -Identity <SystemMessageIdParameter>

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

Syntax

Set-SystemMessage [-Identity] <SystemMessageIdParameter>
 [-Confirm]
 [-DomainController <Fqdn>]
 [-Name <String>]
 [-Original]
 [-Text <String>]
 [-WhatIf]
 [<CommonParameters>]

Parameters (7)

Parameter	Type	Required	What it controls
-Identity	SystemMessageIdParameter	yes	The Identity parameter specifies the custom system message that you want to modify. You can use any value that uniquely identifies the system message. For example:
-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...
-Name	String		The Name parameter specifies a descriptive name for the system message. The maximum length is 64 characters. If the value contains spaces, enclose the value in quotation marks.
-Original	SwitchParameter		The Original switch specifies whether to stop using the custom system message and start using the default system message. You don't need to specify a value with this switch.
-Text	String		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.
-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.