Update New-TransportRule.md

Added clarification for the AttachmentIsUnsupported predicate to the exceptions as well.

Work Item ID in the ADO: 3152875

Author: m-nestorovic

exchange/exchange-ps/exchange/New-TransportRule.md

@@ -1793,12 +1793,16 @@ This parameter specifies an exception or part of an exception for the rule. The
 
 In on-premises Exchange, this exception is only available on Mailbox servers.
 
-The ExceptIfAttachmentIsUnsupported parameter specifies an exception that looks for unsupported file types in messages. Unsupported file types are message attachments that aren't natively recognized by Exchange, and the required IFilter isn't installed. Valid values are:
+The ExceptIfAttachmentIsUnsupported parameter specifies an exception that looks for unsupported file types in messages. Valid values are:
 
 - $true: Look for unsupported file types in messages.
 - $false: Don't look for unsupported file types in messages.
 
-For more information, see [Register Filter Pack IFilters with Exchange 2013](https://learn.microsoft.com/exchange/register-filter-pack-ifilters-with-exchange-2013-exchange-2013-help).
+Rules can inspect the content of supported file types only. If the rule finds an attachment file type that isn't supported, the ExceptIfAttachmentIsUnsupported exception is triggered. 
+
+For the list of supported file types, see [Supported file types for mail flow rule content inspection](https://learn.microsoft.com/exchange/security-and-compliance/mail-flow-rules/inspect-message-attachments#supported-file-types-for-mail-flow-rule-content-inspection).
+
+In Exhange 2013, to extend the list of supported file types, see [Register Filter Pack IFilters with Exchange 2013](https://learn.microsoft.com/exchange/register-filter-pack-ifilters-with-exchange-2013-exchange-2013-help).
 
 ```yaml
 Type: Boolean