Show The BCC Input Field By Default In Microsoft Exchange 2010 Outlook Web App.
This article describes how to show the BCC field by default when composing a new message in OWA 2010. Normally, you need to look at the options page, and enable the BCC checkbox each time you compose a message. As usual, there’s no built-in way to do this, but it can be done with a fairly simple edit.
First, look for the editmessage.aspx file in the C:\Program Files\Microsoft\Exchange Server\v14\ClientAccess\Owa\forms\premium folder. Make a copy of it (important if something goes wrong), and then open it in Notepad. Press F3 to begin a search, and find the text ShowBcc. You should find one instance, about two-thirds of the way down the file. Replace it with the word true (in lower case).
Before the change, the searched text would look like this:
<div id="divWellBcc" <%= ShowBcc ? "" :
After the changes, it should look like this
<div id="divWellBcc" <%= true ? "" :
Save the changes, and next time you compose a message in your OWA, the BCC field should always appear. The only problem is that you can’t now turn it off. Sorry.
As with most of these type of modifications, you will need to check that they still function after each product update. Sometimes your modified file will be replaced by a new one from the update.