how to send pre email in jenkins pipeline code example

Example: send email using jenkins pipeline

pipeline {
    agent any

    stages {
        
       stage('PreBuild-Email') {
           steps {
               script {
                   def mailRecipients = '[email protected]'
                   def jobName = currentBuild.fullDisplayName
                   //emailext body: '''${SCRIPT, template="groovy-html.template"}''',
                   emailext body: '''Hello''',
                       mimeTye: 'text/html',
                       subject: "[Jenkins] Started ${jobName}",
                       to: "${mailRecipients}",
                       replyTo: "${mailRecipients}",
                       recipientProviders: [[$class: 'CulpritsRecipientProvider']]
        }
    }
}
        
        stage('Code Checkout'){
            steps {
                echo 'Fetching Source Code..'
                git credentialsId: 'user-creds', url: 'https://github.com/admin/shopper.git'
               // sh 'pwd'
                //sh 'ls'
            }
        }
        stage('Build') {
             tools {
                   jdk "openjdk-1.8"
                }
            steps {
                echo 'Building Code'
                sh 'java -version'
                withGradle {
                    // some block
                    sh 'pwd'
                  sh './gradlew  test:build'
                    }
            }
        }
        stage('Docker Login') {
            steps {
                echo 'Docker Account Login'
                //sh 'docker login --username=<username> --password=<password>'
                
            }
        }

        stage('Docker Push') {
            steps {
                echo 'Pushing test docker image to Docker-Hub'
                //sh 'docker push example/test'
                
            }
        }
        
        // stage('Email') {
        //     steps {
        //         echo 'Sending Email to Engineering Team'
        //         emailext body: 'Successfully Build  and Push Docker image', subject: 'Successfully Build  and Push Docker image', to: '[email protected]'
                
        //     }
        // }
    }
    
    //     post {
    //     always {
    //         emailext body: 'Successfully Build  and Push Docker image', subject: 'Successfully Build  and Push Docker image', to: '[email protected]'
    //     }
    // }
    
        environment {
        EMAIL_TO = '[email protected]'
    }
post {
        
        success {
            emailext body: 'Check console output at $BUILD_URL to view the results. \n\n ${CHANGES} \n\n -------------------------------------------------- \n${BUILD_LOG, maxLines=100, escapeHtml=false}', 
                    to: "${EMAIL_TO}", 
                    subject: 'Build Success in Jenkins: $PROJECT_NAME - #$BUILD_NUMBER'
        }
        
        failure {
            emailext body: 'Check console output at $BUILD_URL to view the results. \n\n ${CHANGES} \n\n -------------------------------------------------- \n${BUILD_LOG, maxLines=100, escapeHtml=false}', 
                    to: "${EMAIL_TO}", 
                    subject: 'Build failed in Jenkins: $PROJECT_NAME - #$BUILD_NUMBER'
        }
        unstable {
            emailext body: 'Check console output at $BUILD_URL to view the results. \n\n ${CHANGES} \n\n -------------------------------------------------- \n${BUILD_LOG, maxLines=100, escapeHtml=false}', 
                    to: "${EMAIL_TO}", 
                    subject: 'Unstable build in Jenkins: $PROJECT_NAME - #$BUILD_NUMBER'
        }
        changed {
            emailext body: 'Check console output at $BUILD_URL to view the results.', 
                    to: "${EMAIL_TO}", 
                    subject: 'Jenkins build is back to normal: $PROJECT_NAME - #$BUILD_NUMBER'
        }
    }
    
    

    
}