SMTP server response: 530 5.7.0 Must issue a STARTTLS command first

Question

SMTP server response: 530 5.7.0 Must issue a STARTTLS command first

I get this error message when i use mail() function in php script file...

I m using gmail

Answer 1

For Windows, I was able to get it working by enabling TLS for secure communication on the SMTP Virtual server. TLS will not be available on the SMTP virtual server without a certificate. This link will give the steps needed.

https://support.microsoft.com/en-ie/help/4014125/how-to-configure-iis-smtp-for-outgoing-tls-authentication