PHP：获取阅读回执时显示实际图像

Question

So I am working on getting an email read receipt (Laravel and PHP), where I try to update a field in DB when an email is opened.
Description
1. Send an email to a user.
2. Once that user reads the mail, update the message status from "unread" to "read" in the database.

Code I have already added to make it happen
1. Send message id to mail body.
2. Add <img> tag like,

<p><img src="http://www.xyzdomain.com/messagestatus/{{$id}}"></p>

3. Have a function in controller with route for above url, which will do the DB update for me.

Problem
Though the status is successfully updated to "Read" when a user reads that mail. The image shown in mail body is broken because i am passing a url and not image. Can someone guide me about how can I show some image like some transparent background image which won't show a broken image.
Thanks in advance.

Answer 1

You should redirect to an image file after the DB update.. for example, create an image in this url:

http://www.xyzdomain.com/img.png

(Preferably a 1x1 px transparent image)

Then after your DB update redirect using header() to this image file.

<?php

   ... some db updating code ...

   header('Location: http://www.xyzdomain.com/img.png');
   die();

 ?>

This way, the image will not be broken in your client's email. It will actually get an image file after updating the database.