How can one test the rendering of HTML and plain text emails in various email clients, both web-based and native?

To test the rendering of HTML and plain text emails in various email clients, both web-based and native, you can use a tool like Litmus or Email on Acid. These tools allow you to preview how your emails will appear in different email clients, helping you ensure consistent rendering across platforms.

// Code snippet to test rendering of HTML and plain text emails
// Using Litmus API for email testing

$litmus_username = 'your_litmus_username';
$litmus_password = 'your_litmus_password';
$email_content = '<html><body><h1>Hello, world!</h1></body></html>';
$email_subject = 'Testing email rendering';

$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, 'https://your_litmus_account.litmus.com/emails');
curl_setopt($ch, CURLOPT_USERPWD, $litmus_username . ':' . $litmus_password);
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_POSTFIELDS, http_build_query(array(
    'html' => $email_content,
    'subject' => $email_subject
)));
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);

$response = curl_exec($ch);
curl_close($ch);

echo $response;