amavisd-milter then does log this line: could not read from amavisd socket /var/amavis/amavisd.sock: No error: 0
The amavisd-milter code is:
logqidmsg(mlfi, LOG_ERR, "could not read from amavisd socket %s: %s", amavisd_socket, strerror(errno));logqidmsg(mlfi, LOG_DEBUG, "amavisd response line %s", mlfi->mlfi_amabuf);
Apparently there could be a response line. Can you turn on debug mode?