I just tried the first line to install then I tried to run "service ClamAV-freshclam start" I get the following error message. "Failed to start ClamAV-freshclam.service: Unit ClamAV-freshclam.service failed to load: No such file or directory." Sorry I am or followed " The Perfect Server - Debian 8 Jessie (Apache2, BIND, Dovecot, ISPConfig 3)"
I guess you used a different guide to set this up as the perfect server guide does not contain any instructions to setup daily clamav scans and email notifications. Most likely a ine that you altered in the configuration file of clamav is wrong. The error message showed you which command you can run to get the detailed error.
Well this is a different HowTo for ClamAV auto updates once a day with email notifications. I tried to install after the Perfect Server for Jessie.
https://www.howtoforge.com/tutorial/configure-clamav-to-scan-and-notify-virus-and-malware/ This is what I used after install. Does it look like I need to do a clean install of the perfect server cause of the error. I can't even do a freshclam now.
I dont think that a reinstall is required, just check the errir message with the command that is displayed in the error.