Linux Display Pop-up Window Message Box Mail Alert Notification

In the Linux shell script How to create Linux pop-up window & Message Box, Mail alert. Display message notification.
1)gnome-terminal -x sh -c "date|less" >>run the command in new gnome-terminal
2)xterm -e "top -c; sleep 10"
Open the xterm terminal and run the command
3)notify-send "welcome to Linux message box"
4)echo "hello">>/dev/pts/2
pts- pseudo terminal slave / ptm - pseudo terminal master
/dev/pts/1 it is indicate about terminal device file.
5)wall "welcome to studentcpu.com"
It will send the message to All The user who are login.
6)cat msg.txt | wall
              SEND MESSAGE TO REMOTE SYSTEM GUI
When we took the remote connectivity of the other system we can send Notification message to the Graphical windows using these method.using Terminal we can do that But through Graphical we have to export variable DISPLAY=:0.
7)export DISPLAY=:0 && zenity --info --title='Message' --text='Linux redhat '
When we took the remote connection for remote system we can display message on there Graphical window
Using export DISPLAY=0;
7)export DISPLAY=:0 && notify-send "we are looking for linux expert"
it will open small notification message box on the right hand side bottom corner.
9)kdialog --title "New Mail Has Arrived" --passivepopup \
"it will terminate withing 5 minutes" 5
Open the message Box on the Left Hand side Top bottom.