I recently noticed that Bacula installations on CentOS 5.x (primarily 5.5) boxes were not sending out email after job completion. It was baffling as bsmtp worked fine on the command line... at least when I ran it as root. I tried running it as the bacula user (my Bacula director runs as the Bacula user, not root) and it failed:
$ su - bacula -s "/usr/sbin/bsmtp"
-bsmtp: error while loading shared libraries: libbac-5.0.1.so: cannot open shared object file: Permission denied
Ah... I checked the file permissions:
ls -la /usr/lib/libbac-5.0.1.so
-rwxr-x--- 1 root root 330240 Jun 22 12:46 /usr/lib/libbac-5.0.1.so
Simple fix:
chmod o+r /usr/lib/libbac-5.0.1.so
On 64 bit CentOS/Rhel, it will be /usr/lib64/libbac-50.0.1.so
I'm guessing that there was a problem in the spec file (I built it from an srpm.)