Set-OwaMailboxPolicy: fix typo

Author: Schneider

exchange/exchange-ps/exchange/client-access/Set-OwaMailboxPolicy.md

@@ -1309,7 +1309,7 @@ Accept wildcard characters: False
 ### -NPSMailboxPolicy
 This parameter is avaialble only in the cloud-based service.
 
-The NPSMailboxPolicy parameter specifies whether to enable or disable the Net Promoter Score (NPS) survey in Outlook on the web. The survey allows uses to rate Outlook on the web on a scale of 1 to 5, and to provide feedback and suggested improvments in free text. Valid values are:
+The NPSMailboxPolicy parameter specifies whether to enable or disable the Net Promoter Score (NPS) survey in Outlook on the web. The survey allows uses to rate Outlook on the web on a scale of 1 to 5, and to provide feedback and suggested improvements in free text. Valid values are:
 
 - $true: The NPS survey is available in Outlook on the web. This is the default value.