These days I tried some plugin to send e-mail message within bbpress via SMTP. Since my domains email is hosted with Google applications I decided to send my messages via the SMTP server from GMail. I found several articles and tutorials, but a lot of them didn’t worked for me.

Why using GMail for sending mail messages?

First of all it’s FREE! Sure most website owners can use their own SMTP server for sending email messages from their website, but it makes sense even than to use Gmail for sending mail. The chance is big that your websites IP address is on a blacklist if your site is on hosted by a shared web hosting provider. If not or you host your site on your own server, there is always a risk that your IP address get blacklisted. Because of some limitations, the SMTP server from Google is a good choice applications with less than 500 recipients a day, check this information from the Google help pages.

Requirements

You need for this code example a PHP5 enabled web host (I tested only on Linux), the port 465 need to be open and of course you need a GMail or Google Apps account.

SMTP for Gmail tutorial

1. If you don’t have one, register a GMail account or setup your domain for Google applications.
2. Download a recent version of PHPMailer (I used the version 5.02)
3. Check with your web hosting provider if port 465 (TCP out) is open, if not ask him to open that port
4. Include the PHPMailer class file: require_once('phpmailer/class.phpmailer.php');
5. Create those two constant variable to store your GMail login and password. Use the login for your Google application mail if you have one.

   define('GUSER', 'you@gmail.com'); // Gmail username
   define('GPWD', 'password'); // Gmail password

6. Use the following function to send mail messages (add the function in one of your included files):

   function smtpmailer($to, $from, $from_name, $subject, $body) { 
   	global $error;
   	$mail = new PHPMailer();  // create a new object
   	$mail->IsSMTP(); // enable SMTP
   	$mail->SMTPDebug = 0;  // debugging: 1 = errors and messages, 2 = messages only
   	$mail->SMTPAuth = true;  // authentication enabled
   	$mail->SMTPSecure = 'ssl'; // secure transfer enabled REQUIRED for Gmail
   	$mail->Host = 'smtp.gmail.com';
   	$mail->Port = 465; 
   	$mail->Username = GUSER;  
   	$mail->Password = GPWD;           
   	$mail->SetFrom($from, $from_name);
   	$mail->Subject = $subject;
   	$mail->Body = $body;
   	$mail->AddAddress($to);
   	if(!$mail->Send()) {
   		$error = 'Mail error: '.$mail->ErrorInfo; 
   		return false;
   	} else {
   		$error = 'Message sent!';
   		return true;
   	}
   }

   Most of the setting inside the function are required by GMail. While searching for tutorials I found articles with different settings for the port and security. My advice use them as in this tutorial.

7. Call the function within your code:

   smtpmailer('to@mail.com', '', 'from@mail.com', 'yourName', 'test mail message', 'Hello World!');

   Use this more “advanced” usage inside your application:

   if (smtpmailer('to@mail.com', 'from@mail.com', 'yourName', 'test mail message', 'Hello World!')) {
   	// do something
   }
   if (!empty($error)) echo $error;

Advanced setup with fall-back SMTP server

Because of the limit it might be useful to use a secondary SMTP server if the Gmail option didn’t send the message. For this functionality we need to replace the part with the SMTP settings a little bit. First create login/server variables for the 2nd SMTP server:

define('SMTPUSER', 'you@yoursmtp.com'); // sec. smtp username
define('SMTPPWD', 'password'); // sec. password
define('SMTPSERVER', 'smtp.yoursmtp.com'); // sec. smtp server

Next we need to create a if/else statement using the variables for the second server (replace).

function smtpmailer($to, $from, $from_name, $subject, $body, $is_gmail = true) { 
	global $error;
	$mail = new PHPMailer();
	$mail->IsSMTP();
	$mail->SMTPAuth = true; 
	if ($is_gmail) {
		$mail->SMTPSecure = 'ssl'; 
		$mail->Host = 'smtp.gmail.com';
		$mail->Port = 465;  
		$mail->Username = GUSER;  
		$mail->Password = GPWD;   
	} else {
		$mail->Host = SMTPSERVER;
		$mail->Username = SMTPUSER;  
		$mail->Password = SMTPPWD;
	}        
	$mail->SetFrom($from, $from_name);
	$mail->Subject = $subject;
	$mail->Body = $body;
	$mail->AddAddress($to);
	if(!$mail->Send()) {
		$error = 'Mail error: '.$mail->ErrorInfo;
		return false;
	} else {
		$error = 'Message sent!';
		return true;
	}
}

And use the function now as followed:

$msg = 'Hello World';
$subj = 'test mail message';
$to = 'to@mail.com';
$from = 'from@mail.com';
$name = 'yourName';
 
if (smtpmailer($to, $from, $name, $subj, $msg)) {
	echo 'Yippie, message send via Gmail';
} else {
	if (!smtpmailer($to, $from, $name, $subj, $msg, false)) {
		if (!empty($error)) echo $error;
	} else {
		echo 'Yep, the message is send (after hard working)';
	}
}

Both examples are very simple and demonstrate only how-to send mail messages via the SMTP server from Gmail. Of course the user can extend the code to handle HTML messages and attachments etc. If you have any issues with these examples, just let me know. Post a comment here or post to our partner PHP script forum.

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