rfc2821 says that i have to use a fully qualified domain or an ip address enclosed in brackets when connecting to mail servers

how can i make sure my sendmail on linux is using an ip address instead of localhost.localdomain? and will it put it in brackets ?

i need to fix this because mail is being rejecting by some servers


[root@myhostname]# grep .*Sender.address.rejected.* /var/log/maillog

Oct 23 04:05:47 myhostname sendmail[23026]: j9MJPmF5029447: to=<user@theirdomain.com>, ctladdr=<nobody@localhost.localdomain> (99/99), delay=13:39:58, xdelay=00:00:01, mailer=esmtp, pri=1291265, relay=mx.theirmailserver.com. [xx.xxx.xx.xx], dsn=4.2.0, stat=Deferred: 450 <nobody@localhost.localdomain>: Sender address rejected: Domain not found

had to get a new subdomain from my webhost and then edit /etc/hosts and /etc/sysconfig/network and changed the hostname to the new one via the hostname command.

i then performed /etc/init.d/syslog restart

and rebuilt sendmail.cf and restarted sendmail

(fedora core 2)