PHP: Check who had read sent email?

Question

I am sending email to some users and wants to know who had read it, means if some one had read that email then a log file will maintain which contain the email address of th

Answer 1

Please refer RFC-3798 for more details about MDN.

Answer 2

I know this is an old thread but I just had to respond... for those of us who must consider this, I suggest we put ourselves in the place of the people who have to write the anti-spam software to thwart our efforts. Detecting a ? or a .php (or other script/binary extension) inside an image tag would be trivial for me as a postulated 'spam assassin' programmer... just as identifying a 1x1 image would be...

I spent 2.5 yrs as National Digital Director for a presidential campaign that raised $20 million before we even had a candidate -- here's what I had developed for that campaign:

1. At send time (or before), generate a hash on the TO: email address and store that in the db next to the email address.

2. Use the hash we just generated to modify a small, but plainly visible logo in the email and make a copy of the logo with the hash in the logo file name eg: emxlogox.0FAE7E6.png - refer to that unique image in the email for the logo - make a copy of the logo with the hash name in the filename. This particular logo series only ever appears in targeted mass emails. Warn crew members not to copy it for other purposes (or to rename it extensively if they do). The first part of the filename needs to be something that will not appear in the logs in other contexts to speed your parsing and the code you have to craft to sort out false hits.

3. Parse the logs for occurrences of the logo being requested, and extract the hash from the filename to match back against the one email address. And your parsing program can also get the IP address and the time delta it took for them to get and open the email so you can identify highly responsive recipients and the ones who took a week to open the email. Do a geo-lookup on the IP and see if you get a match with the location you already have, and/or start recording their travel patterns (or proxy use patterns). Geo deltas could also be identifying email forwards.

Same hash, of course, is used to record clicks, and also the first and second opt-ins. (Now you have a 'dossier' of multiple opt-ins for responses to those abuse reports and you're protecting your email reputation, too).

This method can also be used to identify who forwards emails to their friends and you ask those 'good forwarders' to join some kind of elite digital volunteer crew, offer them discounts or rewards or whatever is appropriate for your business/project... in essence, that same hash also becomes a referrer code.

You can also ask them to right click on the logo in the email and save it without changing the filename, then post it to 'wherever' (the image should have a memorable, readable, meaningful shortlink on it, not an unreadable bit.ly shortlink). You can then use the Google Search API to identify who helped you out in that fashion and thank them or give them rewards... For this purpose, it helps if the first part of your logo filename is really unique like unsportingly.unique.emxlogox.0FAE7E6.png so you don't have to do millions of Google Search API queries - just search on the unique first part of the filename - and look at the hashes after you get the hits.

You store the links where their copy of the logo appeared in your db to add to your dossier of where on the net they are active and have helped you.

Yes, it's slow and burdensome, but in these days when we say we want to develop a 'relationship' with our email list, it's what you have to do to give individual treatment; identify and reward your friends. And yes, you end up with millions of those hashed filename images in one directory, but storage is cheap and it's worth it to really have that relationship with your peeps.

Answer 3

As the last post was awhile back, I am uncertain as to whether this method still works.

I tested this method on a server running PHP 5.4.30, and it does not seem to output an image.

This is some very simple code:

<img src="http://theservername.com/myaccount_email_read_offline.php">

Note that I removed the querystring and any additional code from this image.

Opening up that separate page, myaccount_email_read_offline.php did display the image.

However, trying to include the image by including a PHP file in its place did not work.

Answer 4

This is next to impossible to do 100% effectively.

1. You could control where the content is stored e.g. http://www.example.com/34hg038g85gb8no84g5 and provide a link in the email to that content, you can then detect when that URL was viewed.

2. Use a method used by MailChimp and other newsletter campaigns, put an invisible image in your email, this image should reside on a server you control, you can then detect when that image is hit when the user opens the email.

Answer 5

Send a beacon image in the emails like so

<img src='http://www.yourserver.com/beacon.php?email_id=$email_id&email_address=$user_address' style='width:1px;height:1px'>

And then use the beacon.php file to log the data. You will then want to output a 1X1 image with appropriate headers.

Important note
Many popular email clients (such as Gmail) now block external images, so this is by far, not fool proof.

Answer 6

Embedding a user specific image (1px blank might be good) in the email and record whether it is hot or not is a fair solution. But the problem Gmail like client block external images by default.