Hi @Sanjana12 ,
Are you able to check the preview of the Image and from there Please copy the Url generated and check it in any of the browsers. In which browsers are you facing the issue?
One of the Possible reasons would be to name the Image with Spaces. In the Url Space will get replaced with %20 which breaks the url and hence no images will get displayed in email.
Regards,
Pravallika.