You could use an image, although it may be more likely that the email layout is done using an HTML table and you can use borders within the table, or if you would prefer a graphic, you can put a cell in between your 2 content cells and have an image in the middle.
You could use an image, although it may be more likely that the email layout is done using an HTML table and you can use borders within the table, or if you would prefer a graphic, you can put a cell in between your 2 content cells and have an image in the middle.