title: Nodemailer is not sending emails in NestJs
body: <p>I have the next configuration for nodemailer package:
  <br></p>
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-js lang-js prettyprint-override"><code>//App module 
  @Module({
    imports: [
      MailerModule.forRoot({
        transport: {
          host: 'localhost',
          port: 3000,
          secure: false,
        },
        defaults: {
          from: '"nest-modules" &lt;modules@nestjs.com&gt;',
        },
        template: {
          dir: __dirname + '/templates',
          adapter: new HandlebarsAdapter(),
          options: {
            strict: true,
          },
        },
      }),
     ...
  })
  export class AppModule {}</code></pre>
  </div>
  </div>
  </p>
  <p>And</p>
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-js lang-js prettyprint-override"><code>//Email service 
  export class EmailService {
    constructor(private readonly mailerService: MailerService) {}
  
    public example(): void {
      this.mailerService
        .sendMail({
          to: 'email@gmail.com', // list of receivers
          from: 'test@nestjs.com', // sender address
          subject: 'Testing Nest MailerModule ✔', // Subject line
          text: 'welcome', // plaintext body
          html: '&lt;b&gt;welcome&lt;/b&gt;', // HTML body content
        })
        .then((r) =&gt; {
          console.log(r, 'email is sent');
        })
        .catch((e) =&gt; {
          console.log(e, 'error sending email');
        });
    }
  }</code></pre>
  </div>
  </div>
  </p>
  <p>I am using my local environement. Tring the code above i get an error in catch block: <code>Error: Greeting never received</code>. Why i get that error and how to send the email without any issue?</p>