Set mailname at the beginning

src/freedombone-base-email

     if [[ $(is_completed $FUNCNAME) == "1" ]]; then
         return
     fi
+
+    echo "$DEFAULT_DOMAIN_NAME" > /etc/mailname
+
     apt-get -y remove postfix
     apt-get -y install exim4 sasl2-bin swaks libnet-ssleay-perl procmail xinetd
 
         chown -R $MY_USERNAME:$MY_USERNAME /home/$MY_USERNAME/Maildir
     fi
 
-    echo "$DEFAULT_DOMAIN_NAME" > /etc/mailname
-
     function_check configure_firewall_for_email
     configure_firewall_for_email
     dpkg-reconfigure --frontend noninteractive exim4-config