How to turn off sendmail

It's not as easy as it used to be to turn off sendmail. Not too long ago, you merely had to add:

sendmail_enable="no"

to your /etc/rc.conf and the sendmail daemon wouldn't start.

But sendmail added an option early in 2003:

Sendmail FAQ, Section 3

And this makes it a little more difficult. In addition, they made it easier to add a different MTA (Mail Transport Agent), like Postfix say. So now you have to follow the instructions in /usr/src/UPDATING:

"20020404:
New sendmail startup scripts have been installed to make it
easier to use alternative MTAs with FreeBSD.  Setting the rc.conf
variable sendmail_enable to "NO" no longer prevents any sendmail
daemons from starting.  Instead, either set sendmail_enable to
"NONE" or change mta_start_script to a script for starting
an alternative MTA.  Setting mta_start_script to "" will
also prevent any MTA from being started at boot."