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

Problem Solved,

I edited the file /etc/postfix/master.cf

and commented

-o smtpd_relay_restrictions=permit_sasl_authenticated,reject

and changed the line from

-o smtpd_tls_security_level=encrypt 

to

-o smtpd_tls_security_level=may

And worked on fine