Well, I don't know what is a "zombie process", but I imagine is not good a thing.
I stop mailscanner, and I start it then and I get the same.
Then I restart the server, and I still having zombies I think.
1734 ? SNs 0:00 MailScanner: starting children
1735 ? ZN 0:01 \_ [MailScanner] <defunct>
1871 ? ZN 0:01 \_ [MailScanner] <defunct>
I had not touched /etc/MailScanner/MailScanner.conf before. What can I check there?