I added a new email domain to my server yesterday. ISPconfig successfully created dkim files and DNS records. When I tested the email domain, I noticed the dkim signature wasn't getting attached to the email header. I discovered the dkim_key for domain.com was missking from the /etc/amavisd/60-dkim file: Code: dkim_key('domain.com', 'default', '/var/lib/amavis/dkim/domain.com.private'); After manually adding this line and restarting dkim and postfix, the dkim signature appeared in the header as expected. My 60-dkim file is owned by root with group amavis with 0750 permissions. Is this a simple ownership or permissions problem? I recently upgraded CentOS, PHP and roundcube mail, just want to be cautious.