Sending email with attachments via flutter_email_sender is not working on Android - flutter

Question

I'm trying to send an email with a pdf attachment using flutter_email_sender, it works fine on iOS but throws Failed to find configured root error on Android. Below is the code.
Future<void> _downloadFile(String url, String filename) async {
var request = await httpClient.getUrl(Uri.parse(url));
var response = await request.close();
var bytes = await consolidateHttpClientResponseBytes(response);
String dir = (await getApplicationDocumentsDirectory()).path;
File file = new File('$dir/$filename');
await file.writeAsBytes(bytes);
setState(() {
_file = file;
});
}
final Email email = Email(
body: 'Email body',
subject: 'Email subject',
recipients: ['email#gmail.com'],
attachmentPath: _file.path,
);
await FlutterEmailSender.send(email);
and the stack trace:
E/MethodChannel#flutter_email_sender: Failed to handle method call
java.lang.IllegalArgumentException: Failed to find configured root that contains /data/data/com.xxx.xx/app_flutter/account_opening.pdf at androidx.core.content.FileProvider$SimplePathStrategy.getUriForFile(FileProvider.java:739)
at androidx.core.content.FileProvider.getUriForFile(FileProvider.java:418)
at com.sidlatau.flutteremailsender.FlutterEmailSenderPlugin.sendEmail(FlutterEmailSenderPlugin.kt:95)
at com.sidlatau.flutteremailsender.FlutterEmailSenderPlugin.onMethodCall(FlutterEmailSenderPlugin.kt:38)
at io.flutter.plugin.common.MethodChannel$IncomingMethodCallHandler.onMessage(MethodChannel.java:222)
at io.flutter.embedding.engine.dart.DartMessenger.handleMessageFromDart(DartMessenger.java:96)
at io.flutter.embedding.engine.FlutterJNI.handlePlatformMessage(FlutterJNI.java:643)
at android.os.MessageQueue.nativePollOnce(Native Method)
at android.os.MessageQueue.next(MessageQueue.java:326)
at android.os.Looper.loop(Looper.java:160)
at android.app.ActivityThread.main(ActivityThread.java:6669)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858)
2019-09-11 13:44:42.484 26003-26003/com.xxx.xx W/ActivityThread: handleWindowVisibility: no activity for token android.os.BinderProxy#98fb11f
2019-09-11 13:44:42.505 26003-26003/com.xxx.xx D/AndroidRuntime: Shutting down VM
2019-09-11 13:44:42.512 26003-26003/com.xxx.xx E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.xxx.xx, PID: 26003
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.xxx.xx/com.kiwi.fluttercrashlytics.CrashActivity}: com.kiwi.fluttercrashlytics.FlutterException: PlatformException(error, Failed to find configured root that contains /data/data/com.xxx.xx/app_flutter/account_opening.pdf, null)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2913)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3048)
at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:78)
at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:108)
at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:68)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1808)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:193)
at android.app.ActivityThread.main(ActivityThread.java:6669)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858)
Caused by: com.kiwi.fluttercrashlytics.FlutterException: PlatformException(error, Failed to find configured root that contains /data/data/com.xxx.xx/app_flutter/account_opening.pdf, null)
at StandardMethodCodec.decodeEnvelope(package:flutter/src/services/message_codecs.dart:564)
at MethodChannel.invokeMethod(package:flutter/src/services/platform_channel.dart:316)
at FlutterEmailSender.send(package:flutter_email_sender/flutter_email_sender.dart:10)
at _EmailWidgetState.build.<fn>(package:gsec/shared/widgets/manualPDFWidget/email_widget.dart:136)
at OnboardingNextButtonWidget.build.<fn>(package:gsec/onboardingScreen/onboard_next_button_widget.dart:84)
at GestureRecognizer.invokeCallback(package:flutter/src/gestures/recognizer.dart:182)
at TapGestureRecognizer._checkUp(package:flutter/src/gestures/tap.dart:365)
at TapGestureRecognizer.acceptGesture(package:flutter/src/gestures/tap.dart:312)
at GestureArenaManager.sweep(package:flutter/src/gestures/arena.dart:156)
at _WidgetsFlutterBinding&BindingBase&GestureBinding.handleEvent(package:flutter/src/gestures/binding.dart:222)
at _WidgetsFlutterBinding&BindingBase&GestureBinding.dispatchEvent(package:flutter/src/gestures/binding.dart:198)
at _WidgetsFlutterBinding&BindingBase&GestureBinding._handlePointerEvent(package:flutter/src/gestures/binding.dart:156)
at _WidgetsFlutterBinding&BindingBase&GestureBinding._flushPointerEventQueue(package:flutter/src/gestures/binding.dart:102)
at _WidgetsFlutterBinding&BindingBase&GestureBinding._handlePointerDataPacket(package:flutter/src/gestures/binding.dart:86)
at ._rootRunUnary(dart:async/zone.dart:1136)
at _CustomZone.runUnary(dart:async/zone.dart:1029)
at _CustomZone.runUnaryGuarded(dart:async/zone.dart:931)
at ._invoke1(dart:ui/hooks.dart:250)
at ._dispatchPointerDataPacket(dart:ui/hooks.dart:159)

Answer 1

It is not possible to attach files from ApplicationDocumentsDirectory since this directory is only accessible from your app. You have to use a directory like ExternalStorageDirectory to be able to send from it. If you do so don't forget to add WRITE_EXTERNAL_STORAGE permission to your app before release.
Cheers.