I don't think so. The sendmail_enable directive operates the SMTP daemon. In other words, it opens a mailserver on your port 25 accepting incoming smtp connections from the world. Probably not what you want
If you have no sendmail-related entries in rc.conf, the defaults in /etc/defaults/rc.conf will be used, and those defaults are that a local Sendmail queue runner will be started at boot time, and that local mail will be processed every 15 minutes.
Code:
grep sendmail /etc/defaults/rc.conf
will reveal all.
Your process list should show:
Code:
970 ?? Is 0:00.17 sendmail: Queue runner@00:15:00 for /var/spool/clientmqueue (sendmail)