how to create socket to yahoo's smtp server? [duplicate]

Question

This question already has answers here:

CakePHP SwiftMailer SMTP TLS OpenSSL Error SSL3_GET_RECORD:wrong version number (3 answers)

Closed 9 years ago.

The problem is I want to connect to yahoo mails's smtp server using stream_socket_client.

$host = 'smtp.mail.yahoo.com';
$port = 587;
$errno = 0;
$errstr = '';

$smtp_conn = stream_socket_client(
    'tls://'.$host . ":" . $port,
    $errno,
    $errstr,
    30
);

and it gives the following error

Warning: stream_socket_client(): SSL operation failed with code 1. OpenSSL Error messages: error:1408F10B:SSL routines:SSL3_GET_RECORD:wrong version number in C:\xampp\htdocs\index.php on line 53

I used phpMailer first and it worked just fine, but I want to do this by myself.

How can I solve this problem? Thank you.

Answer 1

Port 587 (submission) is not used for direct TLS connection, but you need to do a plain connect, read SMTP welcome, send EHLO and read response and then issue a STARTTLS command and read response. Only then (and only after successful response to STARTTLS) you can upgrade the existing socket to TLS. With the Perl tool swaks you can see the dialog:

=== Trying smtp.mail.yahoo.com:587...
=== Connected to smtp.mail.yahoo.com.
<-  220 smtp.mail.yahoo.com ESMTP ready
 -> EHLO my.hostname
<-  250-smtp.mail.yahoo.com
<-  250-PIPELINING
<-  250-SIZE 41697280
<-  250-8 BITMIME
<-  250 STARTTLS
 -> STARTTLS
<-  220 2.0.0 Start TLS
=== TLS started with cipher TLSv1:RC4-SHA:128
=== TLS no local certificate set
=== TLS peer DN="/C=US/ST=CA/L=Sunnyvale/O=Yahoo! Inc./OU=Yahoo Mail/CN=smtp.mail.yahoo.com"

If you want to do a direct SSL connect you have to use port 465 (smtps).