Are there any best practices to follow when setting up imap_open for email retrieval in PHP to ensure smooth and efficient operation?

When setting up imap_open for email retrieval in PHP, it is important to follow best practices to ensure smooth and efficient operation. One key practice is to securely handle credentials by storing them in a separate configuration file outside of the web root. Additionally, it is recommended to use SSL/TLS encryption for secure communication with the mail server. Finally, make sure to properly close the IMAP connection after retrieving emails to free up resources.

// Load credentials from a separate configuration file
$config = include 'config.php';

// Connect to the mail server using imap_open with SSL/TLS encryption
$mailbox = "{localhost:993/imap/ssl}INBOX";
$connection = imap_open($mailbox, $config['username'], $config['password']);

// Check if the connection was successful
if (!$connection) {
    die('Could not connect to the mail server');
}

// Retrieve emails and process them

// Close the IMAP connection to free up resources
imap_close($connection);