How to send mail with To, CC and BCC?

Email headers don’t matter to the SMTP server. Just add CC and BCC recipients to to_addrs when sending emails. For CC, add them to the CC header.

toaddr="[email protected]"
cc = ['[email protected]','[email protected]']
bcc = ['[email protected]']
fromaddr="[email protected]"
message_subject = "disturbance in sector 7"
message_text = "Three are dead in an attack in the sewers below sector 7."
message = "From: %s\r\n" % fromaddr
        + "To: %s\r\n" % toaddr
        + "CC: %s\r\n" % ",".join(cc)
        + "Subject: %s\r\n" % message_subject
        + "\r\n" 
        + message_text
toaddrs = [toaddr] + cc + bcc
server = smtplib.SMTP('smtp.sunnydale.k12.ca.us')
server.set_debuglevel(1)
server.sendmail(fromaddr, toaddrs, message)
server.quit()