My clients are mostly "normal" businesses so they are not interested/able/bothered about learning or using complex solutions to anything. Toddle.com fits the bill for those of them who want to send email newsletters.
Alan and the team at Toddle are the Tuesday push this time around (I am a day late :-)).
It offers design templates for your email (if you think that well designed email newsletters are simple just try it!), pricing is per use (e6 per newsletter) and that is for unlimited numbers.
I have not used this one but would happily do so if I needed a simple solution for a good looking ezine.