How can I send Email from gmail to another email account - dart

Question

I think that this's an issue many coders are facing at the moment.
So let's find a solution:
I already tried ->
mailer2: ^1.2.5
var options = GmailSmtpOptions()
..username = ''
..password = '';
var emailTransport = SmtpTransport(options);
var envelope = Envelope()
..from = ''
..recipients.add(email)
..subject = ''
..html = "<h1>Title </h1>\n\n"
emailTransport.send(envelope)
.then((envelope) => print('Email sent!'))
.catchError((e) => print('Error occurred: $e'));
but the following error message came up:
Unsupported operation: Platform._localHostname
at Object.throw_ [as throw] (http://localhost:63913/dart_sdk.js:4463:11)
at Function._localHostname (http://localhost:63913/dart_sdk.js:54754:17)
at Function.get localHostname [as localHostname] (http://localhost:63913/dart_sdk.js:54810:33)
at get _localHostname (http://localhost:63913/dart_sdk.js:54713:27)
at Function.desc.get [as _localHostname] (http://localhost:63913/dart_sdk.js:4944:15)
at Function.get localHostname [as localHostname] (http://localhost:63913/dart_sdk.js:54666:26)
at mailer.GmailSmtpOptions.new.mailer.SmtpOptions.new
(http://localhost:63913/packages/mailer2/mailer.dart.lib.js:1178:30)
at new mailer.GmailSmtpOptions.new (http://localhost:63913/packages/mailer2/mailer.dart.lib.js:1229:43)
at http://localhost:63913/packages/bestbite_native/web/screens/screen_after_order.dart.lib.js:12394:37
at Generator.next (<anonymous>)
at runBody (http://localhost:63913/dart_sdk.js:37195:34)
at Object._async [as async] (http://localhost:63913/dart_sdk.js:37226:7)
at http://localhost:63913/packages/bestbite_native/web/screens/screen_after_order.dart.lib.js:12392:389
at _RootZone.runUnary (http://localhost:63913/dart_sdk.js:37029:58)
at _FutureListener.then.handleValue (http://localhost:63913/dart_sdk.js:32116:29)
at handleValueCallback (http://localhost:63913/dart_sdk.js:32663:49)
at Function._propagateToListeners (http://localhost:63913/dart_sdk.js:32701:17)
at _Future.new.[_completeWithValue] (http://localhost:63913/dart_sdk.js:32544:23)
at async._AsyncCallbackEntry.new.callback (http://localhost:63913/dart_sdk.js:32566:35)
at Object._microtaskLoop (http://localhost:63913/dart_sdk.js:37290:13)
at _startMicrotaskLoop (http://localhost:63913/dart_sdk.js:37296:13)
at http://localhost:63913/dart_sdk.js:32918:9Error: Unsupported operation: Platform._localHostname
Does anybody has an idea how to send emails in flutter web applications?
(Without opening an email tab)

Answer 1

"mailer2"(and the original package "mailer") imports dart:io which is not available on flutter web and therefore you cannot use this package.
A solution I have used in the past for sending emails is to create an http-triggered cloud function(e.g. Firebase functions, AWS Lambda, netlify functions) that sends the email. You can pass any data you need through the http request and have the cloud function send the email through something like nodemailer in Node.js.
There also may be other services or APIs available that already do what the cloud function does, though I have not seen many and they are not my preferred method