Configuring authenticated email form delivery with PHPMailer

Objective: We have disabled the support for script through mails without authentication along with the up-gradation to Plesk. If a website uses a feedback or any mail sending script, then it has to be updated to ensure that it uses authenticated SMTP relay.

Part 01 : Follow the steps to configure script through mails with PHPMailer SMTP Authentication

The traditional mail() function in PHP does not support SMTP authentication. Hence we recommend the use of PHPMailer class function, which is an open source and secure script for enabling the same:

PHPMailer Installation and sample code - https://github.com/PHPMailer/PHPMailer

Note : The PHPMailer class files can also be found in the attached archive with this KB article. This attached archive has enough examples scripts ready for your help.

Step 01 : Please create an email ID in your hosting account in advance for use in SMTP authentication.

Step 02 : Please update your codebase, downloaded from the GitHub link above, in the /src/PHPMailer.php file starting from line 282 with the email ID and password you created for SMTP authentication, parameters shown below. (Attached Screenshots below)

public $Host = 'localhost'; --> here use your email server hostname as mail.<your-domain-name>
public $Port = 25;

public $SMTPAuth = true;
public $Username = '<Created-Email-ID>';
public $Password = '<Password>';

Part 02 : Follow the steps below if your domain is using Gmail service for email service

Step 01: If your domain is using Gmail for email services, please set the SMTP server to smtp.gmail.com and use port 465 for the connection. Additionally, ensure SSL is enabled in PHPMailer by inserting the following code:

$mail->SMTPSecure = "ssl";

Also don’t forget to enable IMAP and POP access for the mentioned Google apps account and enable access for less secure apps, as shown in the screenshot bellow.

Important: Please make sure not to use the visitor's email id from the feedback form input in 'From' field of the email generated. Due to email server's security settings, emails from remote domains will not be relayed through authenticated SMTP. So use an valid email id from your own domain in the from field of the generated email and pass the visitors email id as information filed in generated message body.

Part 03 : Follow the steps below if WordPress is being used for the script through emails with SMTP authentication.

For WordPress, a plugin is required to enable the SMTP configuration feature.

You can download the necessary plugin from: https://wordpress.org/plugins/wp-mail-smtp