I am fully aware of the limitations on email stats tracking.
I also know that there are privacy and spam score issues with embedded invisible images used to track email opening stats.
However, since most of the 3rd party commercial email sending systems provide stats, my clients are insisting on them too.
My email newsletter system has the following by default:
An invisible (transparent) png image pulled in via a php script that does the tracking. It works well within the limitations of such tracking.
HOWEVER, the system also allows me to nominate a “real” image, such as the logo, to be the stats image.
My question is, “From a spam score point of view, does it matter whether the tracking image is a real, visible image such as the logo rather than a transparent PNG?”
I don’t see this as having a ton of impact. The benefit of the logo being a tracking pixel is minimal if you’re using an image rich email – in fact I can’t see any real reason to use. If you don’t use images in emails, people won’t download the tracking pixel (or any image). If you do use them, browsers will download all the images, pixel included.
Some spam software will identify 1x1 images in html emails and take that as an indicator that the email is spam.
Since any sensible person will have images turned off by default so as to prevent spammers from confirming their email address by including a linked image in the email you will need them to whitelist your sending address in order for them to be able to see any of the images.
The better alternative is to include the images in the email itself so that the spam block on linked images doesn’t stop the images displaying. Of course that makes it impossible to track who opens the email but then the recipient doesn’t want the sender to know that they opened an email in case it turns out to be spam (and that includes spam pretending to come from an email address different from where it actually came from so as to try to appear more legitimate).