error：Real domain name required for sender address。
原因是因为hostname不对，不能是localhost.localdomain。
修改：hostname -v lucifo。
/etc/hosts 中一定是127.0.0.1 localhost.localdomain
mc文件中一定要把 LOCAL_DOMAIN(`localhost.localdomain')dnl
改成LOCAL_DOMAIN(`lucifo')dnl
> jBH0CIxs030054: to=kd [at] netnerd.ca, ctladdr=root (0/0),
delay=00:00:00,
> xdelay=00:00:00, mailer=relay, pri=57738,
relay=[127.0.0.1]
> [127.0.0.1], dsn=4.0.0, stat=Deferred: Connection refused
by
> [127.0.0.1]
Specify *both* IP interfaces in *.mc file you use to generate
sendmail.cf
and recompile it.
DAEMON_OPTIONS(`Port=smtp,Addr=127.0.0.1,
Name=MTA-local')dnl
DAEMON_OPTIONS(`Port=smtp,Addr=192.168.1.100,
Name=MTA-public')dnl