there's a workaround you can try. Create a new distribution or contact group (depending on your Outlook version) and place all your recipients in it. Now prepare your email, but instead of entering an address in the 'To' field, leave it blank.
Now Click on the Bcc field and select your recipient group. Send the message, and each person will receive a personal copy - none of them will know that there are other recipients.
Does that help?