log empty gif module if a connection lasted more than 10s

[Vladan Popovic]

I'm trying to use the log empty gif module to track wether a recipient has read
an email (has kept the email open for more than 10s)

I would like to embed the gif in the email html and if the empty gif is
downloaded measure whether the reader has kept the email open for more than 10
sec. I would like to log that information in the access.log or use post_action /
proxy to convey the uri with additional parameters to a php script.

I've been going through the documentation for a while now but do not seem to
find how to achieve this.

Any help would be appreciated.

Best Regards

Vladan