Quoting Tom Brown <tom at ng23.net>: > I need to set some of our boxes to send mail through our smarthost. In > the sendmail.mc file i have set the smarthost and rebuilt the > sendmail.cf file. When i send a mail locally on the box though i get > this error > > Diagnostic-Code: SMTP; 553 5.1.8 <root at localhost.localdomain>... Domain > of sender address root at localhost.localdomain does not exist > > What else do i need to edit as there is something that talks about > sending from unresolvable domains but this is already allowed i think > > FEATURE(`accept_unresolvable_domains')dnl > > any ideas ? The above 553 error was probably generated on your smarthost. Make sure your host is not called "localhost.localdomain" (in /etc/sysconfig/network). Edit /etc/hosts and make sure your host name is not in the 127.0.0.1 line (put it into separate line with your host's IP address).