I was using my gmail account to send an smtp alert messages to my users email . Example, registration or account blocked etc. I am using a nodemailer and was email were sent
I was using secure: false and I faced the same issue on production and below was the solution that worked for me:
secure: false
const transporter = nodemailer.createTransport({ host: , port: 25, secure: false, logger: true, debug: true, ignoreTLS: true // add this });
Hope this will help someone.