You can use PHP to dynamically send emails to one or more recipients. This can be handy for a lot of reasons, for example: Sending newsletters to a mailing list Sending a "welcome" email to new members of your website A user has just made a purchase and you need to send them a receipt by email Sending an email alert to your technical administrator whenever an error occurs Many more reasons... The PHP mail() Function To send email using PHP, you use the mail() function. This accepts 5 parameters as follows (the last 2 are optional). mail(to,subject,message,headers,parameters) Below is an explanation of the parameters. Parameter Description to Required. The recipient's email address. subject Required. The email's subject line. message Required. The actual email body. headers Optional. Additional header fields such as "From", "Cc", "Bcc" etc. parameters Optional. Any additional parameters. Sending an Email You could send email by simply doing this: Copy to Clipboard mail("homer@example.com", "Thank you for registering!", "Hello Homer, thank you for registering!", "From: ian@example.com"); Although, in reality, you would probably set your parameters up as variables. Also, if the email was triggered by a user, you would probably provide them with feedback to say that the email had been sent. Copy to Clipboard // Set up parameters $to = "homer@example.com"; $subject = "Your password"; $message = "Hello Homer, thanks for registering. Your password is: springfield"; $from = "ian@example.com"; $headers = "From: $from"; // Send email mail($to,$subject,$message,$headers); // Inform the user echo "Thanks for registering! We have just sent you an email with your password."; HTML Emails To send an HTML email, the process is the same, however, you need to provide additional headers (as well as an HTML formatted message). Note that you need to separate each header with a carriage return. Windows For Windows systems, use this code: Copy to Clipboard // Set up parameters $to = "homer@example.com"; $subject = "Your password"; $message = "<p>Hello Homer,</p> <p>Thanks for registering.</p> <p>Your password is: <b>springfield</b></p> "; $from = "ian@example.com"; $headers = "MIME-Version: 1.0" . "\r\n"; $headers .= "Content-type:text/html;charset=iso-8859-1" . "\r\n"; $headers .= "From: $from" . "\r\n"; // Send email mail($to,$subject,$message,$headers); // Inform the user echo "Thanks for registering! We have just sent you an email with your password."; UNIX For UNIX systems, use this code: Copy to Clipboard // Set up parameters $to = "homer@example.com"; $subject = "Your password"; $message = "<p>Hello Homer,</p> <p>Thanks for registering.</p> <p>Your password is: <b>springfield</b></p> "; $from = "ian@example.com"; $headers = "MIME-Version: 1.0" . "\n"; $headers .= "Content-type:text/html;charset=iso-8859-1" . "\n"; $headers .= "From: $from" . "\n"; // Send email mail($to,$subject,$message,$headers); // Inform the user echo "Thanks for registering! We have just sent you an email with your password."; Difference Between UNIX and Windows Code? You probably noticed in the above example that there's a Windows version and a UNIX version. The only difference is in the way the carriage returns are specified. On Windows it's "\r\n", on UNIX it's "\n". The PHP specification stipulates that you should use "\r\n" for creating the carriage returns. This should work fine on Windows systems. UNIX systems however, have a tendency to add "\r" to the "\n", therefore resulting in "r\r\n", which of course, wouldn't work. Therefore, we simply leave out the "\r" on the UNIX version.