I believe that the iOS SDK provides no access to the details of the default mail account (for good reason), but is there any other way to somehow setup MFMailComposeViewController to prefill the BCC field with the "from" address?
Am I overlooking something obvious or is the only way for the user to fill in the BCC herself?
That information is not accessible via the public API.
Make them input their email on first launch? Perhaps search the Address Book for entries like "Me", or something similar?