Description of problem:
psad is configured to use /usr/bin/mail but does not depend on it:
$ egrep '/bin/(mail|whois)' /etc/psad/psad.conf 
mailCmd          /bin/mail
whoisCmd         /usr/bin/whois;
$ rpm -qR psad | egrep 'mail|whois'
$

Version-Release number of selected component (if applicable):
psad-2.4.6-1.fc29.x86_64

How reproducible:
Always

Steps to Reproduce:
1. dnf install psad
2. dnf remove jwhois mailx
3. systemctl start psad
4. journalctl -u psad --no-hostname

Actual results:
Dec 07 19:29:40 systemd[1]: Starting The Port Scan Attack Detector (psad)...
Dec 07 19:29:41 psad[8647]: [*] Could not find mail, edit /etc/psad/psad.conf at /usr/sbin/psad line 11075.
Dec 07 19:29:41 systemd[1]: psad.service: Control process exited, code=exited status=2
Dec 07 19:29:41 systemd[1]: psad.service: Failed with result 'exit-code'.
Dec 07 19:29:41 systemd[1]: Failed to start The Port Scan Attack Detector (psad).

Dec 07 19:43:58 systemd[1]: Starting The Port Scan Attack Detector (psad)...
Dec 07 19:43:59 psad[8882]: [*] Could not find whois, edit /etc/psad/psad.conf at /usr/sbin/psad line 11075.
Dec 07 19:43:59 systemd[1]: psad.service: Control process exited, code=exited status=2
Dec 07 19:43:59 systemd[1]: psad.service: Failed with result 'exit-code'.
Dec 07 19:43:59 systemd[1]: Failed to start The Port Scan Attack Detector (psad).


Expected results:
Successful service launch.