Fix typo in Set-MailUser documentation.

Author: chrisda

exchange/exchange-ps/exchange/Set-MailUser.md

@@ -2507,7 +2507,7 @@ Accept wildcard characters: False
 ### -RemoveDisabledArchive
 This parameter is available only in the cloud-based service.
 
-The RemoveDisabledArchive switch specifies whether to remove the disabled archive that's associated with the mailuser. You don't need to specify a value with this switch.
+The RemoveDisabledArchive switch specifies whether to remove the disabled archive that's associated with the mail user. You don't need to specify a value with this switch.
 
 ```yaml
 Type: SwitchParameter