about sendmail security update

[Gonzalo Suarez]

hello!

i'm a very new freebsd user/admin. i run my own server since 1 month ago, i
've been told about a security issue with sendmail. i read about it on the
security ad
ftp://ftp.freebsd.org/pub/FreeBSD/CERT/advisories/FreeBSD-SA-06:13.sendmail.ascand
I don't know how could i get my system patch or upgraded. some people
tell me to quit using sendmail and try postfix, but i would like to fix
sendmail and try to configure it...

I installed the system with a freebsd5.4 release cd. i downloaded the patch
and when I excuted it i realized that i don't have the source code of
sendmail since i started the installation with de cd-rom standard
installation. what am i supposed to do now? patch or upgrade. what is the
easy way? i have compiled some little C code for college practices and
installed some bsd-ports with make install but  now i'm a little bit lost
here...

thanks for your help.

Gonzalo.