How to send mail with attachments in Flutter? - dart

Question

I found dart plugin called mailer3: "^1.1.9". Previously I create an image in mobile temp directory. In Flutter mobile app I try to send this saved picture using mailer3 plugin as a mail. The mail reach the destination, I don't get error but seems lost the attachment in process.
In dart it works very well and send the attachment as well. In flutter I can use the temp directory to show the image in app but cannot be able attache to mail.
The image location is in the temp folder of the device:
'/data/user/0/com.myApp.myApp/app_flutter/20180700087.jpg'
I can show the image using below code:
new FileImage(File('$newDekontImage'),
Error:
E/flutter (21184): [ERROR:topaz/lib/tonic/logging/dart_error.cc(16)] Unhandled exception:
E/flutter (21184): FileSystemException: Cannot open file, path = '/data/user/0/com.myApp.myApp/app_flutter/20180700087.jpg' (OS Error: No such file or directory, errno = 2)
How to send mail with attachments in Flutter with provided information in this question?
The Flutter Code:
// TODO: SEND MAIL
void _sendMail() async {
if (!_formKey.currentState.validate()) {
return;
} else {
_formKey.currentState.save();
var _options = new GmailSmtpOptions()
..username = “mymailaddress#gmail.com"
..password = “myPassword”;
var _emailTransport = new SmtpTransport(_options);
var _envelope = new Envelope()
..from = "mymailaddress#gmail.com"
..recipients.add(_receiverMailAddress)
..subject = "${_userDekontDetails[0][0].toString()} - Receipt”
..attachments.add(await new Attachment(file: await new File('$newDekontImage')))
..text = "${_userDekontDetails[0][0].toString()} - Receipt"
..html = '<h3>${_userDekontDetails[0][0].toString()} Receipt.</h3>'
'<p>Hi, registered under my name, I am sending the receipt (${widget._currentUserReceiptNo}) with attached to this mail.</p>'
'<p></p>'
'<h5>Regards, </br></h5>'
'${_userDekontDetails[0][0].toString()}';
_emailTransport.send(_envelope)
..then((envelope) => print('Email sent'))
..catchError((e) => print('Error occured: $e'));
}
}

Answer 1

As of this writing, the mailer3 plugin is outdated and mailer is the most up-to-date plugin for sending emails. The mailer plugin currently contains important fixes that mailer2 and mailer3 has. I suggest opting to use mailer package instead of mailer3.
Here's a port of your code snippet from mailer3 to mailer
_sendMail(String username, String accessToken) async {
// Read https://pub.dev/documentation/mailer/latest/smtp_server_gmail/gmailSaslXoauth2.html
var _emailTransport = gmailSaslXoauth2(username, accessToken);
var _envelope = new Message()
..from = "mymailaddress#gmail.com"
..recipients.add("recepient#gmail.com")
..subject = '{EMAIL_SUBJECT_GOES_HERE}'
// Read https://pub.dev/documentation/mailer/latest/mailer/FileAttachment-class.html
..attachments
.add(FileAttachment(File('{FILE_PATH}')))
..text = '{PLAIN_TEXT_GOES_HERE}'
..html = '{HTML_CONTENT_GOES_HERE}';
send(_envelope, _emailTransport)
..then((envelope) => print('Email sent'))
..catchError((e) => print('Error occured: $e'));
}

Answer 2

I have used enough_mail, Hope it will be helpful.
MessageBuilder messageBuilder = MessageBuilder();
Future<bool> onFileSelect(BuildContext context) async {
final result = await FilePicker.platform
.pickFiles(type: FileType.any, allowMultiple: true, withData: true);
if (result == null) {
return false;
}
for (final file in result.files) {
final lastDotIndex = file.path.lastIndexOf('.');
MediaType mediaType;
if (lastDotIndex == -1 || lastDotIndex == file.path.length - 1) {
mediaType = MediaType.fromSubtype(MediaSubtype.applicationOctetStream);
} else {
final ext = file.path.substring(lastDotIndex + 1);
mediaType = MediaType.guessFromFileExtension(ext);
}
messageBuilder.addBinary(file.bytes, mediaType, filename: file.name);
}
return true;
}
Future<void> sendMail(BuildContext buildContext) async {
setState(() {
needToFreezeUi = true;
});
MySnackBar.show(buildContext, MySnackBar.loadingIcon, "Please wait...!");
SmtpClient smtpClient = SmtpClient(domain, isLogEnabled: true);
try {
await smtpClient.connectToServer(
"$serverPrefix.${userInfo.domainName}",
smtpServerPort,
isSecure: isSmtpServerSecure
);
await smtpClient.ehlo();
await smtpClient.authenticate(userInfo.email, userInfo.password);
messageBuilder.from = [MailAddress('', userInfo.email)];
messageBuilder.to = [MailAddress('', toTextEditCtl.text)];
messageBuilder.cc = selectedCCEmailInfos.map((e) => MailAddress('',e.emailAddress)).toList();
messageBuilder.bcc = selectedBCCEmailInfos.map((e) => MailAddress('',e.emailAddress)).toList();
messageBuilder.subject = subjectTextEditCtl.text;
String htmlText = await htmlEditorController.getText();
messageBuilder.addTextHtml(htmlText);
messageBuilder.hasAttachments ? messageBuilder.getPart(
MediaSubtype.multipartAlternative,
recursive: false
) : messageBuilder.addPart(
mediaSubtype: MediaSubtype.multipartAlternative,
insert: true
);
if (!messageBuilder.hasAttachments) {
messageBuilder.setContentType(
MediaType.fromSubtype(MediaSubtype.multipartAlternative)
);
}
MimeMessage mimeMessage = messageBuilder.buildMimeMessage();
SmtpResponse smtpResponse = await smtpClient.sendMessage(mimeMessage);
MySnackBar.hide(buildContext);
if(smtpResponse.isOkStatus){
MySnackBar.show(buildContext,MySnackBar.successIcon,"Mail send successfully");
clearInputFields(buildContext);
}else {
MySnackBar.show(buildContext,MySnackBar.errorIcon,"Something went wrong, please try again!");
}
} on SmtpException catch (e) {
MySnackBar.show(buildContext,MySnackBar.errorIcon,"Something went wrong, please try again!");
}
setState(() {
needToFreezeUi = false;
});
}
============================
dependencies:
enough_mail: ^1.3.4
html_editor_enhanced: ^1.4.0
file_picker: ^3.0.2+2