One of the most off-putting things about a poorly written e-shot is that dreadful, cold, 'mass mailer' feel.
It's not difficult to avoid, though. You just need to change your mindset when writing it.
Here's the trick: don't write an e-shot. Instead, write a personal email communicating your message to a good friend. Then replace the references to their name with your merge fields.
That will give you a good basis for a warm and engaging message.