Editar o arquivo /usr/local/etc/c-icap/c-icap.conf :
/usr/local/etc/c-icap/c-icap.conf
Aumentar os valores StartServers, MaxServers, MinSpareThreads, MaxSpareThreads, ThreadsPerChild.
Editar o arquivo /usr/local/etc/clamd.conf :
/usr/local/etc/clamd.conf
Aumentar o valor de MaxThreads.