PHPMailer: SMTP error: Unable to connect to SMTP host

Question

I've used PHPMailer on several projects, but now I'm stuck. It gives me the error:

SMTP Error: Unable to connect to SMTP host.

I tried sending email from Thunderbird and it worked! But not through PHPMailer... Here are the settings for Thunderbird:

Server name: mail.exampleserver.com

Port: 587

Username: user@exampleserver.com

Secure Authentication: No

Connection Security: STARTTLS

I compared them to the server from my last project using PHPMailer and they are:

Server name: mail.exampleserver2.com

Port: 465

Username: user@exampleserver2.com

Secure Authentication: No

Connection Security: SSL/TLS

My php code is:

$mail = new PHPMailer();
 $mail->IsSMTP(); // send via SMTP
 $mail->Host = SMTP_HOST; // SMTP servers
 $mail->Port = SMTP_PORT; // SMTP servers
 $mail->SMTPAuth = true; // turn on SMTP authentication
 $mail->Username = SMTP_USER; // SMTP username
 $mail->Password = SMTP_PASSWORD; // SMTP password
 $mail->From = MAIL_SYSTEM;
 $mail->FromName = MAIL_SYSTEM_NAME;
 $mail->AddAddress($aSecuredGetRequest['email']);
 $mail->IsHTML(true); // send as HTML

Where did I go wrong?

Answer 1

Since this question comes up so frequently in google, I wanted to share here my solution for a situation where PHP has just been upgraded to version 5.6 (which has stricter SSL behavior).

The PHPMailer wiki has a section about this:

https://github.com/PHPMailer/ PHPMailer/wiki/Troubleshooting#php-56-certificate-verification-failure

Suggested workarounds include the following code:

$mail->SMTPOptions = array(
    'ssl' => array(
        'verify_peer' => false,
        'verify_peer_name' => false,
        'allow_self_signed' => true
    )
);

This should work with PHPMailer 5.2.10 (and later).

NOTE: Apparently, as suggested in this wiki, this should be a temporary solution!