I wrote a list which allows users to add themselves to a mailing list. I currently have 1500+ users on the list, and I was wondering what was the best way to send all these letters out. Could I pass all 1500 at once? Or do I need to break them up? Also, does anyone know why when I pass "Bcc: email@example.com, firstname.lastname@example.org, email@example.com, etc..." as the fourth parameter of send() as it's header, it will not send to any of those users?