Earlier quoted context omitted.
This makes no sense (too abstract of a statement), but here let's try this: $ man systemd | head -4 | tail -1 systemd, init - systemd system and service manager An email daemon (Postfix, Exim, Dovecot, UW-IMAP, Sendmail, etc.) are services running on a server. An "email server" would be a server running a daemon to provide email service in this example.
This makes me think there should be a Linux tool to extract the Nth line of a file. With options to get the N-Mth lines, etc
sed -n '11,500p' < file.txt