How to send an email with a file attachment in Android?

This example demonstrates how do I send an email with a file attachment in android.
Step 1 − Create a new project in Android Studio, go to File ⇒ New Project and fill all required details to create a new project.
Step 2 − Add the following code to res/layout/activity_main.xml.
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
   xmlns:android="http://schemas.android.com/apk/res/android"
   xmlns:tools="http://schemas.android.com/tools"
   android:layout_width="match_parent"
   android:layout_height="wrap_content"
   android:orientation="vertical"
   android:padding="4dp"
   tools:context=".MainActivity">
   <EditText
      android:id="@+id/etTo"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_margin="5dp"
      android:hint="Receiver's Email Address!"
      android:inputType="textEmailAddress"
      android:singleLine="true" />
   <EditText
      android:id="@+id/etSubject"
      android:layout_width="match_parent"
      android:layout_height="wrap_content"
      android:layout_margin="5dp"
      android:hint="Enter Subject"
      android:singleLine="true" />
   <EditText
      android:id="@+id/etMessage"
      android:layout_width="match_parent"
      android:layout_height="200dp"
      android:layout_margin="5dp"
      android:gravity="top|start"
      android:hint="Compose Email"
      android:inputType="textMultiLine" />
   <RelativeLayout
      android:layout_width="match_parent"
      android:layout_height="wrap_content">
   <Button
      android:id="@+id/btSend"
      android:layout_width="80dp"
      android:layout_height="50dp"
      android:layout_margin="5dp"
      android:text="Send" />
   <Button
      android:id="@+id/btAttachment"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_alignParentEnd="true"
      android:text="attachment" />
   </RelativeLayout>
   <TextView
      android:id="@+id/tvAttachment"
      android:layout_width="match_parent"
      android:layout_height="wrap_content"
      android:drawableStart="@drawable/ic_attach"
      android:visibility="gone" />
</LinearLayout>
Step 3 − Add the following code to src/MainActivity.java
import android.app.Activity;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;
public class MainActivity extends Activity {
   EditText etEmail;
   EditText etSubject;
   EditText etMessage;
   Button Send;
   Button attachment;
   TextView tvAttachment;
   String email;
   String subject;
   String message;
   Uri URI = null;
   private static final int PICK_FROM_GALLERY = 101;
   @Override
   protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);
      etEmail = findViewById(R.id.etTo);
      etSubject = findViewById(R.id.etSubject);
      etMessage = findViewById(R.id.etMessage);
      attachment = findViewById(R.id.btAttachment);
      tvAttachment = findViewById(R.id.tvAttachment);
      Send = findViewById(R.id.btSend);
      Send.setOnClickListener(new View.OnClickListener() {
         @Override
         public void onClick(View v) {
            sendEmail();
         }
      });
      //attachment button listener
      attachment.setOnClickListener(new View.OnClickListener() {
         @Override
         public void onClick(View v) {
            openFolder();
         }
      });
   }
   protected void onActivityResult(int requestCode, int resultCode, Intent data) {
      if (requestCode == PICK_FROM_GALLERY && resultCode == RESULT_OK) {
         URI = data.getData();
         tvAttachment.setText(URI.getLastPathSegment());
         tvAttachment.setVisibility(View.VISIBLE);
      }
   }
   public void sendEmail() {
      try {
         email = etEmail.getText().toString();
         subject = etSubject.getText().toString();
         message = etMessage.getText().toString();
         final Intent emailIntent = new Intent(android.content.Intent.ACTION_SEND);
         emailIntent.setType("plain/text");
         emailIntent.putExtra(android.content.Intent.EXTRA_EMAIL, new String[]{email});
         emailIntent.putExtra(android.content.Intent.EXTRA_SUBJECT, subject);
         if (URI != null) {
            emailIntent.putExtra(Intent.EXTRA_STREAM, URI);
         }
         emailIntent.putExtra(android.content.Intent.EXTRA_TEXT, message);
         this.startActivity(Intent.createChooser(emailIntent, "Sending email..."));
      } catch (Throwable t) {
         Toast.makeText(this, "Request failed try again: "+ t.toString(), Toast.LENGTH_LONG).show();
      }
   }
   public void openFolder() {
      Intent intent = new Intent();
      intent.setType("image/*");
      intent.setAction(Intent.ACTION_GET_CONTENT);
      intent.putExtra("return-data", true);
      startActivityForResult(Intent.createChooser(intent, "Complete action using"), PICK_FROM_GALLERY);
   }
}
Step 4 − Add the following code to androidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android" package="app.com.sample">
   <uses-permission android:name="android.permission.INTERNET" />
   <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
   <uses-permission android:name="android.permission.READ_INTERNAL_STORAGE" />
   <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
   <application
      android:allowBackup="true"
      android:icon="@mipmap/ic_launcher"
      android:label="@string/app_name"
      android:roundIcon="@mipmap/ic_launcher_round"
      android:supportsRtl="true"
      android:theme="@style/AppTheme">
      <activity android:name=".MainActivity">
         <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
         </intent-filter>
   </activity>
</application>
</manifest>
Let's try to run your application. I assume you have connected your actual Android Mobile device with your computer. To run the app from android studio, open one of your project's activity files and click Run icon from the toolbar. Select your mobile device as an option and then check your mobile device which will display your default screen −
Click here to download the project code.