SMTP Error: 454 4.7.0 Too many login attempts, ple

Question

I have set up SMTP server with gmail account. It was working fine till few days back. When I checked the logs I found below entry in it:

SMTP Error: 454 4.7.0 Too many login attempts, please try again later.

I have restarted SMTP service twice. I have checked the configuration that was set up using this link. Everything is same as we have set up. I have restarted the SMTP server & the machine too.

I have checked for 2 step verification settings. It is not enabled. I have checked for "less secure" apps settings and it is set to Enabled as suggested here.

I have checked apps enabled as suggested here using below link.

https://security.google.com/settings/security/permissions?pli=1

But no apps are added. Can anyone suggest anything that I need to look for? Thanks in advance.

Answer 1

please follow the instructions below:

• Open Gmail from a browser and only sign into the account you're trying to add. Be sure to be signed out of all your other accounts

  Go to this link: https://accounts.google.com/b/0/displayunlockcaptcha and click Continue or confirm.

  Now Test your program it will work fine

Answer 2

It is because you are attempting to create a new smtp connection for each email. You need to use SMTP pool.

Please see:

DELIVERING BULK MAIL

POOLED SMTP

Pooled smtp is mostly useful when you have a large number of messages that you want to send in batches or your provider allows you to only use a small amount of parallel connections.

If you are using Node-mailer:

const transporter = nodemailer.createTransport({
    host: 'smtp.gmail.com',
    port: 465,
    secure: true,
    pool: true, // This is the field you need to add
    auth: {
       user: '[e-mail]',
       pass: 'your_password' 
}});

Then, you need to close the pool once you send all the emails.

transporter.close();

Answer 3

The Issue resolved with the TCP port changing to 587 from 25 in Outbound Connections settings in SMTP Server.