Prerequisite : https://www.sandeeprao.net/preparing-for-configuring-secure-mail-server-using-postfix-dovecot-spamassassin-and-opendkim/ Install required packages #apt install -y razor #apt install -y amavisd-new dovecot-core dovecot-imapd dovecot-lmtpd dovecot-mysql dovecot-sieve haveged mailutils mariadb-server opendkim opendkim-tools p7zip postfix postfix-mysql postgrey spamassassin Create require vmail user and group #groupadd -g 5000 vmail #useradd -g vmail -u 5000 vmail -d /var/vmail Create mailbox directory #mkdir -p /var/vmail #chown -R…