Many an admin has wondered if DSN (Delivery Status Notifications – Message Delays and NDRs) messages, or Over-the-limit quota messages could be modified. In versions of Exchange prior to Exchange 2007, the answer has always been no, or at least there was no official supported way to do this. I've seen a few utilities to modify the quota messages, but definitely nothing to modify the DSN messages. Thankfully, with Exchange 2007, you now have the ability to add/modify TONS of this information. A few examples.

Modify DSN messages.

Exchange allows you to modify two type of DSN messages. Those associated with 4.x.x error codes (400-level errors codes are transient, retry-able error codes – something like 421 service not available), and those associated with 5.x.x error codes (500-level error codes are permanent fatal errors – like 550 relay denied)

The usage of the MSH command to modify a System DSN is as follows. We'll change the relaying denied message (that's my favorite).

The format of this command is:

New-SystemMessage -DsnCode <EnhancedStatusCode>-Internal <$true | $false> -Language <CultureInfo>-Text String> [-DomainController <String>] [-TemplateInstance <MshObject>]

Following that format, we input the following:

New-SystemMessage -DsnCode 5.7.1 -Language En -Internal $false -Text "Whatever text you want to put in here"

Once you hit Enter, it will now save it as a Custom DSN message for the DSN code that you specified.

If you later want to remove your custom DSN message, you can either issue the command

Set-SystemMessage –identity –original $true, where an example of the identity would be En\External\5.7.1

Modify Quota Messages

Ok – there are several different quota messages that can be configured, including:

* WarningMailboxUnlimitedSize Issued when a mailbox that has no prohibit send quota or prohibit receive quota exceeds the specified mailbox warning limit.* WarningPublicFolderUnlimitedSizeIssued when a public folder that has no prohibit send quota or prohibit receive quota exceeds the specified public folder warning limit.* WarningMailboxIssued when a mailbox that has a prohibit send quota or prohibit receive quota exceeds the specified mailbox warning limit.* WarningPublicFolderIssued when a public folder that has a prohibit send quota or prohibit receive quota exceeds the specified public folder warning limit.* ProhibitSendMailboxIssued when a mailbox that has a prohibit send quota exceeds the specified mailbox size limit.* ProhibitPostPublicFolderIssued when a public folder that has a prohibit send quota exceeds the specified public folder size limit.* ProhibitSendReceiveMailBoxIssued when a mailbox that has prohibit send quota and prohibit receive quota exceeds the specified mailbox send and receive size limit.

The format of the command is:

New-SystemMessage -QuotaMessageType <QuotaMessage> -Language En -Text "Text string"

As an example, if you want to change the quota message that applies to mailboxes that have a limit that prohibits both sending and receiving mail, you would use the following command.

New-SystemMessage –QuotaMessageType ProhibitSendReceiveMailbox –Language En –Text "Put your text in here"

Have fun with these! I for one am glad that this capability will now be present in Exchange.