Update Set-OwaVirtualDirectory.md

Typo fixes

Author: chrisda

exchange/exchange-ps/exchange/client-access-servers/Set-OwaVirtualDirectory.md

@@ -336,7 +336,7 @@ Accept wildcard characters: False
 ```
 
 ### -AllowedMimeTypes
-The AllowedMimeTypes parameter specifies the MIME extentions of attachments that allow the attachments to be saved locally or viewed from Outlook on the web. The default values are:
+The AllowedMimeTypes parameter specifies the MIME extensions of attachments that allow the attachments to be saved locally or viewed from Outlook on the web. The default values are:
 
 - image/bmp
 
@@ -459,7 +459,7 @@ Accept wildcard characters: False
 ```
 
 ### -BlockedMimeTypes
-The BlockedMimeTypes parameter specifies MIME extentions in attachments that prevent the attachments from being saved locally or viewed from Outlook on the web. The default values are:
+The BlockedMimeTypes parameter specifies MIME extensions in attachments that prevent the attachments from being saved locally or viewed from Outlook on the web. The default values are:
 
 - application/hta
 
@@ -1167,7 +1167,7 @@ Accept wildcard characters: False
 ```
 
 ### -ForceSaveMimeTypes
-The ForceSaveMimeTypes parameter specifies the MIME extentions in attachments that only allow the attachments to be saved locally (not opened). The default values are:
+The ForceSaveMimeTypes parameter specifies the MIME extensions in attachments that only allow the attachments to be saved locally (not opened). The default values are:
 
 - Application/futuresplash
 
@@ -2640,7 +2640,7 @@ Accept wildcard characters: False
 ### -WebReadyMimeTypes
 This parameter is available only in Exchange Server 2010 and Exchange Server 2013.
 
-The WebReadyMimeTypes parameter specifies the MIME extentions of attachments that allow the attachments to be viewed by WebReady Document Viewing in Outlook on the web. The default value is all supported MIME types:
+The WebReadyMimeTypes parameter specifies the MIME extensions of attachments that allow the attachments to be viewed by WebReady Document Viewing in Outlook on the web. The default value is all supported MIME types:
 
 - application/msword