Emails are marked as read before the contact actually opened it

Emails are marked as read before the contact actually opened it

Zoho CRM places an invisible image on each email sent via the CRM email tool. When this image is downloaded, the email is marked as read.

If you preview the email in the Zoho CRM email section before the they do, the image will be downloaded and it will mark it as read. There is no way for the tool to know who downloaded the image. Just that it was downloaded.