[RESOLVED] "open email" result

[vinny199]

Hi,

I'm trying to do something I have no idea how it is done:

Commercial mass emailers / newslttter patforms can gather data when an email sent via their platform has been simply opened by the recipient.

how do they do that?

I would like to do that for myself, but can't understand where to start.

I presume when the newsletter is opened, that it sends a message back to a web page that posts the info into the database.

but what is that command "when newsletter is opened..."

Where do i start?

Can someone advise?

Many thanks,

Vinny

[NogDog]

Most likely an image in the email that points (via its src attribute) to a script. Probably part of the reason many mail tools now do not automatically display remote images unless/until you click on some button to allow it.

[sneakyimp]

Yeah the basic idea is to send an HTML email (use PHPMailer if you are unsure how to do this -- it has some helpful features) and include a reference to an image on your site which is actually a PHP file with some extra query string after it:

<img src="http://yourdomain.com/tracking_image.php?userid=[e-mail]">

That PHP file can run queries on your database to increment the count for the email address found in $GET['userid'] and then just pass through the right headers and image data to send a GIF when requested:

<?php
/* put your code here to update the counts for $_GET['userid'] */

header("Content-type: image/gif"); //or jpeg, etc. depending
readfile("/home/user/tracking_gif"); //send the GIF file data

Ideally the image file would be really small -- 1 pixel by one pixel -- to reduce the strain on your server.

[dagon]

you don't need a 'real' image

	$image = imagecreate(1, 1);
	$bgColor = imagecolorallocate ($image, 0, 0, 0);
	header("Expires: Mon, 26 Jul 1997 05:00:00 GMT");
	header("Last-Modified: " . gmdate("D, d M Y H:i:s") . " GMT");
	header("Cache-Control: no-store, no-cache, must-revalidate");
	header("Cache-Control: post-check=0, pre-check=0", false);
	header("Pragma: no-cache");
	header('Content-type: image/jpeg');
	imagejpeg($image);
	imagedestroy($image);

[NogDog]

Or just send a "404 Not Found" header and be done with it. 😉

[dagon]

that would result in a broken image silly

[NogDog]

dagon;10902394 wrote:

that would result in a broken image silly

Eh, you stick it down at the very end of the message body, and who cares? :p

But seriously, if you're going to display an image as part of the message anyway, just use that image.

[dagon]

NogDog;10902395 wrote:

Eh, you stick it down at the very end of the message body, and who cares? :p

The clients who say, "what's that red x dong there?"

NogDog;10902395 wrote:

But seriously, if you're going to display an image as part of the message anyway, just use that image.

All our images are embedded in the email, except the metrics one.

[NogDog]

I would think it would be faster to actually have a 1x1-pixel file to serve up via readfile() than to use the image functions; but I've not tested it, and sometimes performance bottlenecks can be non-intuitive (depending on the quality of your intuition, I suppose).

[bradgrafelman]

What about combining NogDog's 404 error along with:

<img src="http://yourdomain.com/tracking_image.php?userid=[e-mail]" style="display: none">

[dagon]

outlook 2007 does not support display, yes its the worlds suckiest email client, but most used by business users.

[vinny199]

Thanks guys,

Very helpful,

I get the idea.

I'll have a go.

Thanks,

Vinny

[dalecosp]

Please mark your thread RESOLVED.

Thanks.