If this is the initial configuration of sendmail, then edit:
repleace, FEATURE(`msp’, `[127.0.0.1]’)dnl
with, FEATURE(`msp’, `[<ip-of-mail-host>]’)dnl
or with, FEATURE(`msp’, `[<domain-name-of-mail-host>]’)dnl
Then, in /etc/mail, run:
# make all install
Otherwise, edit /etc/mail/submit.cf (about line: 114) to have:
Neither of these methods should require a restart of sendmail. At least this was the case on my machine.