[gate1:~] # cat /etc/rc.conf
...
jail_list="mail"
jail_mail_rootdir="/opt/jail/mail"
jail_mail_hostname="mail.corpX.un"
jail_mail_interface="le0"
jail_mail_ip="192.168.X.10"
jail_mail_devfs_enable="YES"
jail_mail_devfs_ruleset="devfsrules_jail"

[gateN:~] # cat /usr/local/etc/ha.d/haresources
gate1.corpX.un gmirror jailserv

[gateN:~] # cat /usr/local/etc/ha.d/resource.d/jailserv
#!/bin/sh

case $1 in
start)
        /etc/rc.d/jail forcestart mail
        ;;
stop)
        /etc/rc.d/jail forcestop mail
        ;;
esac

exit 0