I will now set up a simple hands-on example that illustrates how the "Mailer" class can be used to send MIME email messages. Thus, below I included the complete definition of the class, along with a short script that will send a trivial message by using the class in question.

Here's the corresponding code sample:

// include MIME mailer class

class Mailer{

var $sender;

var $recipient;

var $subject;

var $headers=array();

function Mailer($sender,$recipient,$subject,$message){

// validate incoming parameters

if(!preg_match("/^.+@.+$/",$sender)){

trigger_error('Invalid value for email sender.',E_USER_ERROR);

}

if(!preg_match("/^.+@.+$/",$recipient)){

trigger_error('Invalid value for email recipient.',E_USER_ERROR);

}

if(!$subject||strlen($subject)>255){

trigger_error('Invalid length for email subject.',E_USER_ERROR);

}

if(!$message){

trigger_error('Invalid value for email message.',E_USER_ERROR);

}

$this->sender=$sender;

$this->recipient=$recipient;

$this->subject=$subject;

$this->message=$message;

// define some default MIME headers

$this->headers['MIME-Version']='1.0';

$this->headers['Content-Type']='multipart/mixed;boundary="MIME_BOUNDRY"';

$this->headers['From']='<'.$this->sender.'>';

$this->headers['Return-Path']='<'.$this->sender.'>';

$this->headers['Reply-To']=$this->sender;

$this->headers['X-Mailer']='PHP 4/5';

$this->headers['X-Sender']=$this->sender;

$this->headers['X-Priority']='3';

}

// create text part of the message

function buildTextPart(){

return "--MIME_BOUNDRYnContent-Type: text/plain; charset=iso-8859-1nContent-Transfer-Encoding: quoted-printablennn".$this->message."nn";

}

// create message MIME headers

function buildHeaders(){

foreach($this->headers as $name=>$value){

$headers[]=$name.': '.$value;

}

return implode("n",$headers)."nThis is a multi-part message in MIME format.n";

}

// add new MIME header

function addHeader($name,$value){

$this->headers[$name]=$value;

}

// send email

function send(){

$to=$this->recipient;

$subject=$this->subject;

$headers=$this->buildHeaders();

$message=$this->buildTextPart()."--MIME_BOUNDRY--n";

if(!mail($to,$subject,$message,$headers)){

trigger_error('Error sending email.',E_USER_ERROR);

}

return true;

}

}

// create a new instance of the 'Mailer' class

$mailer=&new Mailer('alejandro@mydomain.com,'mybuddy@yourdomain.com','Testing mailer class','Hello buddy. How are you?');

// send MIME email message

if($mailer->send()){

echo 'Message was sent successfully.';

}

As you can see, sending MIME-compliant messages with this basic mailer class is a no-brainer process that can be tackled with minor hassles. In the above example, I first created a new instance of the class with the appropriate message's arguments (i.e. the respective sender, recipient, subject, and text) and then sent the message via the "send()" method. It's that simple.

Of course, there's plenty of room to improve the functionality of the previous mailer class, but all of these possible modifications will be implemented throughout the course of the upcoming tutorials in the series. In the meantime, play around with the class and use it to familiarize yourself with sending MIME-compliant email messages with PHP.

Final thoughts

In this first chapter of the series, I walked you through building a basic mailer class that has the capacity to send text-based messages that fit the specification of MIME email. As you saw earlier, the class is very simple to code and use. And due to its flexible structure, it can be extended with minor efforts.

In the next article, I'll be teaching you how to improve the functionality of the class in order to provide it with the capacity to send different types of attachments. Don't miss the next article!