Here is a simple steps to disable Sendmail on your FreeBSD server,

You can try these two methods:

1. If you don't want to restart your server, you can try this command

[code]$/etc/rc.d/sendmail stop[/code]

2. You can also disable Sendmail at the startup config file, you'll need to change the following 4 lines in /etc/defaults/rc.conf

[code]$nano /etc/defaults/rc.conf 

## change below to NO

sendmail_enable="NO"
sendmail_submit_enable="NO"
sendmail_outbound_enable="NO"
sendmail_msp_queue_enable="NO"

## save and exit.[/code]

You'll need to restart your FreeBSD server to make sure your sendmail is not up and running again.