Sometimes if you want to disable Sendmail on your FreeBSD server, you can try those two methods:
- If you don't want to restart your server (In case of emergency):
# killall sendmail
- If you want to disable Sendmail at the startup period, you'll need to add the following 4 lines to /etc/rc.conf :
sendmail_enable="NONE" sendmail_submit_enable="NO" sendmail_outbound_enable="NO" sendmail_msp_queue_enable="NO"
And you'll need to restart your FreeBSD server.