To install bacula with MySQL (after you do this):

sudo apt-get install mysql-server bacula-director-mysql

Then you have to set up exim4, the mail system. Choose:

mail sent by smarthost; no local mail

After you install the MySQL version of the bacula director, you can install the rest of bacula this way, and also install some recommended packages:

sudo apt-get install bacula
sudo apt-get install dds2tar scsitools sg3-utils

I had these notes from an earlier set-up of exim4:
Look into setting up /etc/aliases later to redirect mail to more useful places. Also, make sure the domain of the outgoing address is one known to the outside world (e.g. jadesystems.ca) or the SMTP server will probably reject the message.