We are trying to get "Tracking Email Opening" to work, using Compound Templating on 2013 SP1. We have followed the instructions as found here: http://docs.sdl.com/LiveContent/content/en-US/SDL%20Tridion%20full%20documentation-v1/GUID-2D0A7D1A-555D-4D31-97FD-D82F9A576AF4#addHistory=true&filename=GUID-00841438-80F3-46DE-BB81-084C2859D715.xml&docid=GUID-00841438-80F3-46DE-BB81-084C2859D715&inner_id=&tid=&query=&scope=&resource=&toc=false&eventType=lcContent.loadDocGUID-00841438-80F3-46DE-BB81Tracking e-084C2859D715mail opening.
When Previewing or Publishing, we will find this output in the published HTML:
[*__TrackOpen__*]
What step(s) did we miss to get the tracking image displayed?