Marketing Email Images Not Rendering in Outlook (Gmail Works Fine)

Hi HubSpot Community!

I’m running into an issue where images in our HubSpot Marketing emails populate correctly in Gmail but do not display in Outlook  (both internal and external recipients) or in HubSpot preview. Instead, recipients see an image link.

Here’s what we’ve observed so far:

• Images hosted on HubSpot CDN or external hosts like Cloudinary display fine in Gmail.

• Outlook desktop and web clients (both internal Bozzuto users and external recipients) fail to render the images.

• Images are HTTPS and in standard formats (PNG/JPG).

• Removing query parameters from image URLs or using a simple standalone image may improve rendering, but not consistently.

We suspect this could be related to Outlook’s handling of external images, corporate security filters, or HubSpot’s query-parameter-based image URLs.

We’re looking for guidance on:

1. Best practices for ensuring images render reliably in all Outlook clients.

2. Recommendations for email setup or image hosting in HubSpot to maximize compatibility.

3. Any known issues with HubSpot Marketing emails and Outlook rendering.