Nest mailer throws an error Mailer send Error: Error: Missing credentials for "PLAIN", Why?

Question

Node.js

Added a module to Nest for sending messages in this form:

SenderModule

import { Module, HttpModule, HttpService } from '@nestjs/common';
import { SenderService } from './sender.service';
import { MailerModule } from '@nestjs-modules/mailer';
import { HandlebarsAdapter } from '@nestjs-modules/mailer/dist/adapters/handlebars.adapter';

@Module({
  imports: [
    MailerModule.forRootAsync({
      useFactory: () => ({
        transport: {
          service: 'gmail',
          auth: {
            user: process.env.MAIL_ADDRESS,
            pass: process.env.MAIL_PASSWORD,
          },
        },
        defaults: {
          from: '"vlntmgmt" <[email protected]>',
        },
        template: {
          dir: __dirname + '/templates',
          adapter: new HandlebarsAdapter(),
          options: {
            strict: true,
          },
        },
      })
    }),
  ],
  providers: [SenderService],
  exports: [SenderService]
})
export class SenderModule { }

Service file of this module

import { Injectable, HttpService } from '@nestjs/common';
import { MailerService } from '@nestjs-modules/mailer';

@Injectable()
export class SenderService {
  constructor(private readonly mailerService: MailerService, private httpService: HttpService) { }

  async sendEmail(email: string, message: string, messageHTML?: string) {
    await this.mailerService.sendMail({
      to: email,
      from: '"vlntmgmt" <[email protected]>',
      subject: 'vlntmgmt noreply message',
      text: message,
      html: `<b>${messageHTML ? messageHTML : message}</b>`
    })
      .then(() => { console.log("Mailer sended to", email) })
      .catch((err) => { console.log("Mailer send Error:", err) });
    return true;
  }
}

When submitting, I get an error with the logs:

Mailer send Error: Error: Missing credentials for "PLAIN"
     at SMTPConnection._formatError (/node_modules/nodemailer/lib/smtp-connection/index.js:784:19)
     at SMTPConnection.login (/node_modules/nodemailer/lib/smtp-connection/index.js:448:38)
     at /node_modules/nodemailer/lib/smtp-transport/index.js:271:32
     at SMTPConnection.<anonymous> (/node_modules/nodemailer/lib/smtp-connection/index.js:215:17)
     at Object.onceWrapper (events.js:420:28)
     at SMTPConnection.emit (events.js:314:20)
     at SMTPConnection._actionEHLO (/node_modules/nodemailer/lib/smtp-connection/index.js:1313:14)
     at SMTPConnection._processResponse (/node_modules/nodemailer/lib/smtp-connection/index.js:942:20)
     at SMTPConnection._onData (/node_modules/nodemailer/lib/smtp-connection/index.js:749:14)
     at TLSSocket.SMTPConnection._onSocketData (/node_modules/nodemailer/lib/smtp-connection/index.js:195:44) {
   code: 'EAUTH',
   command: 'API'
 }

Disabled check for insecure connections in mail. Mail and password from the mail, respectively, are correct.
What could be the problem?

Answer 1

possible answers
Most likely there are not enough tokens

Answer 2

Console processes.env.MAIL_ADDRESS, will your result be or undefined?