Configuring smtp settings and then sending the mail through shell script

I have make an menu in which first option is to start and second is to stop the services

 echo "Please enter the appropriate choice for doing the operations"
        echo "
        1) STOP Services        
        2) START Services 
        
    case $choice in
        1)
            echo "*************Stopping Services**************"
            stopAll.sh
            ;;
        2)
            echo "*************Starting Services**************"
            startAll.sh
            ;;

now please advise I want to add the functionality of email also in it that is lets say if some one stop the services by pressing the 1 option then a mail should be launched with the subject that services are stopped and with the body also that services are stopped at that time when the option 1 is pressed ,

Now i have some specific settings of the mail server from which the mail will be send to the users as shown below..

email.smtp.host=12.120.94.54
email.smtp.port=1341

Now the users id abc@gfty.com

please advise how to customize and the add the functionality of email I want to do the smtp host and port settings within the mail and then want to send the mail, please advise.

I would recommend just using the OS mailer:

echo "User $USER ran STOP at `date`" | mail -s "your subject line" abc@gfty.com

Let your OS sort out how to get the mail to the target. If you need to tweak your locally running sendmail/postfix/etc config then do that first.

Otherwise you'll have to create/install a full-blown mail client first.