Since upgrading our mail server to Win2k3 and Exchange 2k3 (enterprise) over the holidays, we have been unable to send mail to certain domains, including AOL, Yahoo and others. The messages just sit in the queues and then time out. We're behind a pix firewall. I've checked the message boards and made sure that our IP has entered PTR and A records for us, but that doesn't seem to have helped. Any thoughts? Thanks. Jan Mt. Pleasant