[SSHGuard-maintainers] sshguard for CentOS 5.3

[Kelvin Ma <bk...@hk...>]

I have several CentOS 5.3 servers. I want to use sshguard but I also wish that it will send notification email upon blocking IP address.
I know sshguard 2.1 ~2.4 which has backend can support this feature.

Can I install sshguard 2.1 on CentOS 5.3. However, I notice that sshguard need run systemd which is absent in CentOS 5.3.
What version of sshguard should I install?
How about CentOS 6?

Best Regards,
Kelvin