I have RH 6.1 with Sendmail, and using linuxconf. I have a permanent connection to the internet. I can send mail out to any domain. My domain is host.domain.name, I can send mail from the mail server at domain.name, and it works. When I send a message from an outside domain it kicks back an error saying "Host name lookup failure". This is the weird part, the smtp server from an outside domain will try and send the message for five days. I will receive the message on about the second day. Thank you in advance.