What are common pitfalls to avoid when sending HTML emails using PHP?
Common pitfalls to avoid when sending HTML emails using PHP include not properly setting the Content-Type header to indicate that the email is HTML formatted, not properly escaping special characters in the email content, and not including a plain text alternative for recipients who cannot view HTML emails. To address these issues, make sure to set the Content-Type header to "text/html", use htmlspecialchars() or htmlentities() to escape special characters, and include a plain text version of the email.
// Set the Content-Type header to indicate that the email is HTML formatted
$headers = 'MIME-Version: 1.0' . "\r\n";
$headers .= 'Content-type: text/html; charset=utf-8' . "\r\n";
// Escape special characters in the email content
$email_content = '<html><body><p>Hello, this is an example HTML email.</p></body></html>';
$email_content = htmlspecialchars($email_content);
// Include a plain text alternative for recipients who cannot view HTML emails
$plain_text_content = 'Hello, this is an example plain text email.';
// Send the email with both HTML and plain text content
mail($to, $subject, $email_content, $headers);