wp_mail_smtp.php

<?php
defined( 'ABSPATH' ) OR exit;
/**
 * Plugin Name: (WCM) PHPMailer SMTP Settings
 * Description: Enables SMTP servers, SSL/TSL authentication and SMTP settings.
 * Allow less secure apps in: https://myaccount.google.com/u/2/lesssecureapps?pageId=none
 */
add_action( 'phpmailer_init', 'phpmailerSMTP' );
function phpmailerSMTP( $mail )
{

	//Tell PHPMailer to use SMTP
	$mail->isSMTP();
	//Enable SMTP debugging
	// 0 = off (for production use)
	// 1 = client messages
	// 2 = client and server messages
	$mail->SMTPDebug = 2;
	//Set the hostname of the mail server
	$mail->Host = 'smtp.gmail.com';
	// use
	// $mail->Host = gethostbyname('smtp.gmail.com');
	// if your network does not support SMTP over IPv6
	//Set the SMTP port number - 587 for authenticated TLS, a.k.a. RFC4409 SMTP submission
	$mail->Port = 587;
	//Set the encryption system to use - ssl (deprecated) or tls
	$mail->SMTPSecure = 'tls';
	//Whether to use SMTP authentication
	$mail->SMTPAuth = true;
	//Username to use for SMTP authentication - use full email address for gmail
	$mail->Username = "xxx@gmail.com";
	//Password to use for SMTP authentication
	$mail->Password = "xxx";
	
}