Currently evaluating em client and it is excellent, apart from having to remember to press return twice to space paragraphs.
I know there are posts on this subject but no real conclusions. Currently I am using Thunderbird as my main client and it does have a setting for paragraph spacing in HTML (Use Paragraph format instead of Body Text by default) which works well as it is natural to have a blank line between paragraphs - pressing return leaves a blank line and shift+return keeps lines together.
Please add this as an option to turn on paragraph spacing for HTML, simple as it is it would make using em client so much easier to use.