To change the logo for only a single email:
- Navigate to Content > Email and select an email to edit
- Scroll down to your Logo and click to edit.
- Please note that this section is only available for templates with logo module. Check to see that you have the logo module under Settings > Edit template.
- Click the box next to Override default logo for this page, and then click the pencil button to replace with a different image.
- Choose an image from the File Manager or upload a new image.
- Click Use Image.
- Click Done.
To change the default logo for all templates including email and COS pages, see How do I change the default logo for all templates?