To check mail for viruses I use sendmail milter, which connect to (commercial) antivirus program drweb. Both sendmail and drweb live on one debian linux host (behind a firewall), and can connect to each other over Unix socket or TCP socket. Ports for sendmail and drweb to communicate (in case of using TCP socket) are filtered out from the Internet by firewall (iptables).
My question is: Using which socket (Unix or TCP) is more secure in this case? Thank you, Mikhail.