Image Generation in Open Time Email Campaigns
Open Time Email (OTE) campaigns and templates use image generation as a background process. When you publish an OTE template, the image generation process kicks off and determines whether eligible products and associated OTE Item Templates need images. It then creates an initial set of images for all items that match the item type of the template and stores them on the Marketing Cloud Personalization CDN. The images generated by this process appear in the OTE Simulator and the emails you provision via OTE campaigns.
The following table describes common problems that can occur with images in OTE campaigns and their causes.
|Missing or invisible images||Occurs because there was an error in processing an image generation, which could be due misconfiguration, such as when using locales, or customer CDN throttling limits.|
|Blurry images||Adding style, height, and width tags can cause blurriness. These tags aren’t necessary in order to generate images. In fact, images without style tags appear crisper.|
|Differences between OTE Simulator and test emails||Occurs due to an error with the |
|Differences between OTE Simulator and Recipe Simulator or OTE Item Template preview||Occurs because the OTE Simulator uses the images in the CDN, whereas the other features providing previews or simulation don’t.|
|Differences between images and current product data||Occurs because the product and item template pair hasn’t been identified as needing image generation. Products are tagged for image generation only if they meet eligibility requirements and have properties referenced in a published item template that have changed values. Factors that determine image generation eligibility: |
Image generation errors that occur due to customer throttling limits are outside of the control of Marketing Cloud Personalization. These errors usually appear as default transparent pixel images, or erroneous images with missing data. You can find additional error information in internal logs.
There are a few things you can do to troubleshoot and fix issues related to images in OTE campaigns and templates.
To fix throttling issues, see if adding the following user agent and HTTP headers to an allowlist to either avoid throttling or have a higher threshold:
|Where||Add to Allowlist|
You can improve the clarity of images in your templates by making a few changes to your Personalization OTE and Salesforce Marketing Cloud templates.
Clone the Personalization OTE template with blurry images.
Add the exact HTML comment
<!--useHidpi-->to any valid HTML position in the template. For example, you can prepend the HTML comment at the beginning of the OTE template.
This comment is case-sensitive.
Specify width constraints for the Personalization OTE template's image slots. For example, if the image slots on your Personalization OTE template are 190 px wide:
- Add the attribute
px) to the
<img>tag that uses the OTE image as its
- Modify the
styleattribute to include
width: 100%; max-width: 190px.
The width and height of image containers could require adjustments based on the HTML structure and desired final appearance. Keep in mind that standard CSS rules apply when using OTE images in HTML documents.
- Add the attribute
Use the template in a new campaign that uses the cloned HiDPI version of the original Personalization OTE template.
If you've already deployed the original campaign with blurry images, you must carry out this step in production.