Error in gradle file:More than one file was found with OS independent path 'META-INF/LICENSE'

Question

I am getting the following error when I try to build my project. This error occurs when I was trying to add JavaMail api in my project.

Error:Execution failed for task ':app:transformResourcesWithMergeJavaResForDebug'.
> More than one file was found with OS independent path 'META-INF/mailcap.default'

This is my gradle file:

apply plugin: 'com.android.application'

android {
    compileSdkVersion 26
    defaultConfig {
        applicationId "com.persi.eatery"
        minSdkVersion 21
        targetSdkVersion 26
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"

    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
    productFlavors {
    }



}

dependencies {
    implementation fileTree(include: ['*.jar'], dir: 'libs')
    implementation 'com.android.support:appcompat-v7:26.1.0'
    implementation 'com.android.support.constraint:constraint-layout:1.0.2'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'com.android.support.test:runner:1.0.1'
    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.1'
    implementation 'com.android.support:design:26.1.0'
    compile 'com.google.firebase:firebase-database:11.0.2'
    compile 'com.google.firebase:firebase-auth:11.0.2'
    compile 'com.sun.mail:android-mail:1.6.1'
    compile 'com.sun.mail:android-activation:1.6.1'
    compile project(':library')

}

apply plugin: 'com.google.gms.google-services'

My library gradle:

apply plugin: 'com.android.library'

android {
    compileSdkVersion 23
    buildToolsVersion '26.0.2'

    defaultConfig {
        minSdkVersion 8
        targetSdkVersion 23
        versionCode 1
        versionName "1.0"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }

}

I have tried to implement the following solution which I found on the similar question: On gradle:3.0.0 More than one file was found with OS independent path 'META-INF/ASL2.0'

packagingOptions {
    exclude 'META-INF/DEPENDENCIES'
    exclude 'META-INF/LICENSE'
    exclude 'META-INF/LICENSE.txt'
    exclude 'META-INF/license.txt'
    exclude 'META-INF/NOTICE'
    exclude 'META-INF/NOTICE.txt'
    exclude 'META-INF/notice.txt'
    exclude 'META-INF/ASL2.0'
}

But it does not solve the problem. Ps I have not much idea about gradle files