Turns out you're right. It wasn't my list, it was a client's, so I didn't send out the email. They do have a mailman list, but they didn't use it for some reason, as is evident by the lack of the List headers etc.

Thanks.

On Fri, 2007-12-21 at 06:50 -0500, Charles Marcus wrote:

On 12/20/2007, Joel Plane (joel.plane@gmail.com) wrote:

...

I have set up a mailing list for sending out a monthly newsletter. It works well, except all recipients can see each others email addresses in the To field. How do I prevent this?

Either use the BCC field, or use a real mail list software like mailman... but you certainly aren't using mailman for this list, so don't know why you are posting your question here...