If you happen to be using XAMPP as your development environment, the sending of emails via localhost will not work by default if not configured properly.

php.ini

The first step is to modify a configuration file called php.ini located under C:\xampp\php unless you installed XAMPP on a different location, you need to do some adjustments.

Another way to locate the php.ini file is to create a PHP file under C:\xampp\htdocs and name it phpinfo.php and in this file, enter the following code:

<?php echo phpinfo(); ?>

Save the file and visit http://localhost/phpinfo.php in your browser and search for Loaded Configuration File and from there you will see where the php.ini file is located on your hard drive.

Open the php.ini file and search for sendmail_path. It’s commented out by default, so uncomment it by removing the semicolon at the beginning, set its value to "\"C:\xampp\sendmail\sendmail.exe\" -t" then save.

sendmail_path = "\"C:\xampp\sendmail\sendmail.exe\" -t"

sendmail.ini

Modify the sendmail.ini file which is located under C:\xampp\sendmail and make the following changes accordingly:

smtp_server = smtp.gmail.com
smtp_port = 587
auth_username = YOUR_USERNAME@gmail.com
auth_password = YOUR_PASSWORD

Under auth_username and auth_password, make sure that it’s a valid gmail account.

Restart Apache Server

In order for changes to take effect, restart the Apache Server. There are many ways to do this, here’s one way using the XAMPP Control Panel.

On the panel, click Services and after that, right click on the Apache2.4 and click Restart.

Send a Test Email

To wrap up, create a PHP file under C:\xampp\htdocs and name it mail.php and in this file, enter the following code:

<?php
$recipient = 'YOUR_USERNAME@gmail.com';
$subject = 'Test Email';
$message = 'This is a test email.';
mail($recipient, $subject, $message);
?>

Change the $recipient to your gmail username and visit http://localhost/mail.php in your browser.

You should receive the test email in your inbox.