Open tracker for email with external CSS pixel option.
For more context read this blog post.
Parameters:
- p: A unique value to track.
- ext_css (optional): Generate CSS that loads an "external CSS pixel".
- css_pixel: Auto generated by ext_css option that records an external CSS pixel open.
Logging notes:
- Request contains only "p", it will be logged as "Regular pixel fetched".
- Request contains "ext_css", it will be logged as "External CSS fetched".
- Request contains "css_pixel", it will be logged as "CSS pixel fetched".
To use regular pixel:
<img src="https://myserver.com/path/to/pixel.php?p=mypixel123" width=1>
To use External CSS pixel (only for email clients that support external CSS):
<link rel="stylesheet" href="https://myserver.com/path/to/pixel.php?p=mypixel123&ext_css=1">