Why aren't my opens being tracked?
Track Opens is not on by default. You need to turn on track opens in each autoresponder and broadcast you want to track.
The track opens setting is found in the email creation tool, here:
How does track opens work?
We insert an invisible one pixel image into each email. When the email is opened, the invisible image loads from our server and we know someone opened that email. These images are called web bugs.
I have Track Opens on, I opened the email, and it still didn't register!
There are a number of reasons we may not be able to track any particular email. Here are some of the most common:
Many email providers block images.
For example, Gmail by default blocks all images. Instead of the images loading, a bar like this is displayed:
If the person chooses not to display images, the web bug image will not load and we cannot tell if the email was opened.
Some email providers use plain-text email, and block HTML.
Displaying an image requires HTML, and if the email provider blocks inline HTML, we can't load the web bug to track the open.
Privacy enhancing software blocks web bugs.
The Silver Lining
You're more successful than you think you are! All of the above produce false negatives, that being someone opened your email, but that fact isn't reported. So your open rate is always higher than the statistics can prove.
Can I track opens in SMS or voicemail?
No, SMS and Voicemail can not track opens. Only email is trackable. The web bug trick works only for email and web pages.