I was really displeased with the time sendmail added to my startup. Why not just background it, I wondered? So I did, and it now starts in its own sweet time while the login screen comes up.
Is this a terrible idea? Is it dangerous? No idea. It seems to work just fine for me, and darn, it sure is faster. I would be curious to see what others have to say.
After you have successfully set up sendmail, edit /System -> Library -> StartupItems/ -> Sendmail -> Sendmail, and find these two lines:
/usr/sbin/sendmail -bd -q1hEnclose them in parentheses, and put an ampersand immediately after:
/usr/sbin/sendmail -C /etc/mail/submit.cf -q1h
(Restart and (hopefully) enjoy.
/usr/sbin/sendmail -bd -q1h
/usr/sbin/sendmail -C /etc/mail/submit.cf -q1h
) &
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