Gmail saves all images. What does that mean for my open ratio?

Since December 2013, Gmail stores all images of emails on their own proxy servers. Images in your newsletter are then displayed from Gmail's (Google's) cache; they are no longer requested through our servers (every time).

When your Gmail subscriber opens your newsletter, Gmail first saves the images in your newsletter. Gmail changes the unique URL of the image in your newsletter and replaces it with a reference to their cache. Google caches your images for at least 24 hours. Your Gmail subscriber will then read your newsletter using the images stored by Google.

As a user of an email marketing programme such as Laposta, Gmail's approach has a number of advantages. Gmail subscribers will now by default get to see your newsletter in its full design (i.e. including all images).

Until recently, Gmail always asked for permission before displaying images. Because your newsletter is immediately displayed in the correct layout (with all images), there is a good chance that the open ratio (the percentage of unique opens) will increase a bit. A newsletter with a beautiful layout and a nice header is more likely to be read and clicked on than a newsletter with alt-text, of which the images still have to be retrieved (even with just one click).

With this measure, Gmail also offers its users extra protection against (images in) emails that threaten the security of their PC, tablet or smartphone (e.g. viruses and malware).

This approach also has a (minor) disadvantage. In order to register whether your newsletter has been opened, Laposta (like other suppliers) uses an invisible, extremely small image in your newsletter. When your subscriber views the images in his newsletter our servers receive a signal through the invisible image; this is how Laposta knows that your newsletter has been opened.

With Gmail's approach, we can still register the first time your newsletter is opened. The open ratio, which shows the percentage of unique opens, is therefore also correct for Gmail subscribers. However, due to the storage of the images in the Gmail cache, Laposta can no longer register (at least for the first 24 hours) a second or subsequent open from Gmail subscribers.