HTML emails are created with tables, images, and inline styling. That seems very outdated by cutting edge web standards, but that's the best way to get your message across if your business has a mailing list. The problem is, a designer doesn't know where that email will end up. If not coded correctly, various email clients will chew and spit your code out so it looks like a pile of leaves on the front lawn. Designing with tables is the lowest common denominator and the only bullet-proof way to style an email with images with consistent results.
I design the images of the email in Photoshop and use the slice tool to divide areas such as hyperlinks. The Save To Web feature creates the code and aligns the table cells. Photoshop doesn't create the best code for emails, so I have to change some of the styling attributes.
Here is a collection of emails that I have designed over the past few years. I started designing each Replay Photo email differently, but eventually we established a new identity and started streamlining the designs. There are a couple of emails for different clients, but the majority are Replay Photos.