Message rejected under suspicion of SPAM Nodejs, Yandex, Firebase functions

Question

I am trying to send email from my NodeJs Server using Yandex. Below is the process of creating transporter

 let transporter = nodemailer.createTransport({
            service: 'Yandex',
            auth: {
                user: process.env.EMAIL,
                pass: process.env.PASSWORD
            }
        });

But it always fails showing the below messege:

{ Error: Message failed: 554 5.7.1 [2] Message rejected under suspicion of SPAM; https://ya.cc/1IrBc 1578999406-wC5neov7vv-ui00GIiO

 at SMTPConnection._formatError (F:\ProjectFolder\Office\MXQ\Backend\mxq_server_firebase_functions\functions\node_modules\nodemailer\lib\smtp-connection\index.js:605:19)
 at SMTPConnection._actionSMTPStream (F:\ProjectFolder\Office\MXQ\Backend\mxq_server_firebase_functions\functions\node_modules\nodemailer\lib\smtp-connection\index.js:1478:34)
 at SMTPConnection._responseActions.push.str (F:\ProjectFolder\Office\MXQ\Backend\mxq_server_firebase_functions\functions\node_modules\nodemailer\lib\smtp-connection\index.js:968:2

2) at SMTPConnection._processResponse (F:\ProjectFolder\Office\MXQ\Backend\mxq_server_firebase_functions\functions\node_modules\nodemailer\lib\smtp-connection\index.js:764:20) at SMTPConnection._onData (F:\ProjectFolder\Office\MXQ\Backend\mxq_server_firebase_functions\functions\node_modules\nodemailer\lib\smtp-connection\index.js:570:14) at TLSSocket._socket.on.chunk (F:\ProjectFolder\Office\MXQ\Backend\mxq_server_firebase_functions\functions\node_modules\nodemailer\lib\smtp-connection\index.js:522:47) at TLSSocket.emit (events.js:198:13) at TLSSocket.EventEmitter.emit (domain.js:448:20) at addChunk (_stream_readable.js:288:12) at readableAddChunk (_stream_readable.js:269:11) at TLSSocket.Readable.push (_stream_readable.js:224:10) at TLSWrap.onStreamRead [as onread] (internal/stream_base_commons.js:94:17) code: 'EMESSAGE', response: '554 5.7.1 [2] Message rejected under suspicion of SPAM; https://ya.cc/1IrBc 1578999406-wC5neov7vv-ui00GIiO', responseCode: 554, command: 'DATA' }

Is it a problem with Yandex or from my side?

Answer 1

I had the same problem as you, but not all mailboxes can't accept emails. Then, I found the answer in the official support documentation: https://yandex.com/support/mail/bounces/other/message-rejected-under-suspicion-of-spam.html?lang=en

Answer 2

It is on your side, I had such an error before with another provider (not yendex), and solved it by signing the email, you need to get a DKIM and sign your email with it.