Hello Sebastian, I found the problem, and we were both right (that's worth saying :-))
It seems that systemd doesn't start clamd daemon with the right user / group that's why the rigth on the socket are not consistent when clamav-daemon (clamd) is started by systemd. lstat() failed on: /var/spool/clamsmtp/clamsmtpd.EfRJY5 The following modification solve the problem: /lib/systemd/system/clamav-daemon.service ---------------------------------------------------------------------------------------------------------------------- [Unit] Description=Clam AntiVirus userspace daemon Documentation=man:clamd(8) man:clamd.conf(5) http://www.clamav.net/lang/en/doc/ Requires=clamav-daemon.socket # Check for database existence ConditionPathExistsGlob=/var/lib/clamav/main.{c[vl]d,inc} ConditionPathExistsGlob=/var/lib/clamav/daily.{c[vl]d,inc} [Service] #ExecStart=/usr/sbin/clamd --foreground=true ##### XQ 26/04/2016 add config file ExecStart=/usr/sbin/clamd -c /etc/clamav/clamd.conf --foreground=true ExecReload=/bin/kill -USR2 $MAINPID StandardOutput=syslog ##### XQ 26/04/2016 add user and group User=clamav Group=clamav ---------------------------------------------------------------------------------------------------------------------- Specifying User / Group seems enough, however to be sure I added the config file in the ExecStart line. I made also the same for clamav-freshclam.service ---------------------------------------------------------------------------------------------------------------------------------- [Unit] Description=ClamAV virus database updater Documentation=man:freshclam(1) man:freshclam.conf(5) http://www.clamav.net/lang/en/doc/ # If user wants it run from cron, don't start the daemon. ConditionPathExists=!/etc/cron.d/clamav-freshclam [Service] #ExecStart=/usr/bin/freshclam -d --foreground=true ## XQ 26/04/2016 adding conf files and others options not sure that's useful ExecStart=/usr/bin/freshclam -d --quiet --config-file=/etc/clamav/freshclam.conf --foreground=true StandardOutput=syslog ## XQ 26/04/2016 adding a kill options not sure that's useful ExecReload=/bin/kill -USR2 $MAINPID ##### XQ 26/04/2016 add user and group User=clamav Group=clamav [Install] WantedBy=multi-user.target ------------------------------------------------------------------------------------------------------------------------------------------------------------- I'm not familiar with systemd, however I'm surprised that when /etc/init.d/clamav-daemon is somethink like 400 lines, systemd is something like 10 lines. But still I'm not familiar with systemd. Please would you tell me if those modifications make sense, or if those shall be made elsewhere in the system. Best regards XQ