To upload an image in your email marketing campaigns, you will need to do the following:
Drag and drop an image block into your email (the Image icon looks like a small picture with mountains on it). Then look for the button called Browse Server.
A new window will open when you click this button that will allow you to upload a file. Look for the button that says Upload at the top. When you click on this icon, you'll see a button labeled Choose File. Click on this icon to browse for your image. When you're finished browsing for your image, click on the Upload Selected File button. Double-click on the image to select it.
Now that you have double-clicked on the image, you will see its path in the URL box in the previous window called Image Properties. Click on the Ok button to apply the changes. Once you do this, you'll see the image appear in the message content.