Update Set-Mailbox.md

Updates to MessageCopyForSendOnBehalfEnable and MessageCopyForSentAsEnable parameters to indicate user mailboxes and shared mailboxes per Issue #1337.

Author: chrisda

exchange/exchange-ps/exchange/mailboxes/Set-Mailbox.md

@@ -4227,13 +4227,13 @@ Accept wildcard characters: False
 ```
 
 ### -MessageCopyForSendOnBehalfEnabled
-**Note**: This parameter is available only for shared mailboxes.
+**Note**: Previously, this parameter was available only for shared mailboxes. In Exchange Online or Exchange 2016 CU6 or later, this parameter is also available for user mailboxes.
 
-The MessageCopyForSendOnBehalfEnabled parameter specifies whether to copy the sender for messages that are sent from a shared mailbox by users that have the "send on behalf of" permission. Valid values are:
+The MessageCopyForSendOnBehalfEnabled parameter specifies whether to copy the sender for messages that are sent from a mailbox by users that have the "send on behalf of" permission. Valid values are:
 
-- $true: When a user sends a message from the shared mailbox by using the "send on behalf of" permission, a copy of the message is sent to the sender's mailbox.
+- $true: When a user sends a message from the mailbox by using the "send on behalf of" permission, a copy of the message is sent to the sender's mailbox.
 
-- $false: When a user sends a message from the shared mailbox by using the "send on behalf of" permission, a copy of the message isn't sent to the sender's mailbox. This is the default value.
+- $false: When a user sends a message from the mailbox by using the "send on behalf of" permission, a copy of the message isn't sent to the sender's mailbox. This is the default value.
 
 You give users permission to send on behalf of a mailbox by using the GrantSendOnBehalfTo parameter on the mailbox.
 
@@ -4250,13 +4250,13 @@ Accept wildcard characters: False
 ```
 
 ### -MessageCopyForSentAsEnabled
-**Note**: This parameter is available only for shared mailboxes.
+**Note**: Previously, this parameter was available only for shared mailboxes. In Exchange Online or Exchange 2016 CU6 or later, this parameter is also available for user mailboxes.
 
-The MessageCopyForSentAsEnabled parameter specifies whether to copy the sender for messages that are sent from a shared mailbox by users that have the "send as" permission. Valid values are:
+The MessageCopyForSentAsEnabled parameter specifies whether to copy the sender for messages that are sent from a mailbox by users that have the "send as" permission. Valid values are:
 
-- $true: When a user sends a message from the shared mailbox by using the "send as" permission, a copy of the message is sent to the sender's mailbox.
+- $true: When a user sends a message from the mailbox by using the "send as" permission, a copy of the message is sent to the sender's mailbox.
 
-- $false: When a user sends a message from the shared mailbox by using the "send as" permission, a copy of the message isn't sent to the sender's mailbox. This is the default value.
+- $false: When a user sends a message from the mailbox by using the "send as" permission, a copy of the message isn't sent to the sender's mailbox. This is the default value.
 
 In Exchange Online, you give a user permission to send as a mailbox by running this command: `Add-RecipientPermission <Mailbox> -AccessRights SendAs -Trustee <User>`.