There is no straightforward built in functionality for this. What you can do is create the blue dots (or whatever image you like) and set the cell.imageView.image property. I asked on stackoverflow about a problem I faced which is the images weren’t looking nice when a cell is selected. Here is how it looked (first image for “unread” cells andÂ second for “read” cells)
What is needed is to set a transparent background for the images. Thanks to this post I found a way of masking the images. I’m using the function posted on that website with the following images. Blue dot for “unread” cells, white dot for “read” mails, and the mask image. Feel free to use these images but they are not the typical shiny iphone images. If you know how to make one of those please comment.