I need a Coldfusion Email Open Tracking solution

I need to track email opens. This is for important emails such as flight bookings for clients.

The email is sent using cfmail. I tried something I found that is basically just a image tag referencing a cfm page with url parameter that is included in the HTML email

<cfmail to="someaddress.com" from="someaddress.com" subject="SUBJECT" type="HTML">
 <img src="http://somedomain.com/test.cfm?id=1" />
</cfmail>

This does not work. I only tested on Gmail.

I have seen some examples in PHP but don't know PHP. Anyone tried this with CF?

Solution

make sure your test.cfm looks like this

<cfparam name="URL.id" default="">
    <cftry>
        <cfquery>
            UPDATE
        </cfquery>
        <cfcatch>
        </cfcatch>
    </cftry>

<cfcontent type="image/jpg" file="#application.ABSOLUTE_PATH#resources\img\pixel_white.jpg">