Assuming comma separated emails, here is the "product" in Python:

    import random, string
    email_list = "a@b.com, c@d.com".split(', ')
    random.shuffle(email_list)
    print string.join(email_list, ', ')

If the entire recipient list isn't disclosed to the recipients, then there would be no need to randomize it. So, bcc meets his goal of not disclosing the particular order in which he entered the email addresses.

Granted, in rare cases, it is desirable to disclose all recipients' email addresses to each other, but I'd personally prefer it if that were the exception, rather than common practice.