Issue
You have been sending live emails (non-samples) to yourself or colleagues to test functionality of an upcoming email blast, and even though you may be opening the email, you are not seeing the open email activity on the Lead Activity Log.
Solution
Note that there may be a slight delay between opening the email, and the activity displaying on the Log.
Marketo considers an "open" to be when the images in the email are downloaded, specifically a single-pixel tracking image. The recipient may be receiving the emails and viewing them, but not downloading the images. This would not count as an "open." Please note that since text-only emails have no images, so they will never log an Open activity.
If the images are being downloaded, and you are still not seeing the activity after about 5 minutes, check to make sure there are no duplicate leads that are logging the activity instead. If you need further assistance, please contact Marketo Support.
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