Some clarity is needed. HTML Tables should only ever be used for tabular data and not for pure presentational purposes (that’s what CSS is for). Well, that’s according to HTML5 and best practice standards for website design. When creating an email marketing campaign however just forget about best practice as tables rule the world for email! Creating a newsletter to send via email means that tables must be used for presentation. In fact nested tables are the order of the day so just forget about modern web design in email.
If you look at the HTML code for an email, you will see that it is made up of nested tables. The email itself is a larger table, each block (the greeting, introduction, coupon, etc.) is a table, and each block contains tables. Constant Contact
The reason for this throwback to the 1990s (i.e. using tables for presentation) is because of the way that various email readers handle CSS and HTML. Some email readers are way ahead of others however some are just plain archaic. Below is an example of how the same email looks in two of the most popular email clients; Gmail and Outlook 2007. Notice how the same content and style sent to two of the biggest email readers just looks so different.