What are the common errors or issues that can arise when sending confirmation emails in PHP applications?

One common issue when sending confirmation emails in PHP applications is that the email may end up in the recipient's spam folder. This can happen due to various reasons such as improper email headers or content triggering spam filters. To solve this issue, make sure to set proper email headers, use a reliable email service provider, and avoid using spam-triggering words in the email content.

// Example code snippet to set proper headers when sending confirmation emails
$to = "recipient@example.com";
$subject = "Confirmation Email";
$message = "This is a confirmation email.";
$headers = "From: sender@example.com\r\n";
$headers .= "Reply-To: sender@example.com\r\n";
$headers .= "MIME-Version: 1.0\r\n";
$headers .= "Content-Type: text/html; charset=ISO-8859-1\r\n";

// Send the email
mail($to, $subject, $message, $headers);