Hi,
Just to have a clear understanding of the editors, please note that the drag & drop aditor is not using your default cms editor.
The drag & drop editor is based on a customized TinyMCE engine. Apart from the drag & drop editor you can also work with html templates in Acymailing, which does use your default editor you have set in your cms.
Initially I assumed you were using the drag & drop editor. However, after you mentioned changing the editor to the JCE website editor I thought I was wrong and you were actually using html templates, thus using the website's editor (TinyMCE or JCE). Hence, giving you the wrong answer afterwards.
Now this is clear. When you import articles in the drag & drop editor the <p> tags are not stripped out. By default the bottom margin of the <p> element is zero.
This is done because most people do not know the difference between ENTER and SHFT-ENTER. They just hit ENTER twice to start a new paragraph. No worries, it's on the TODO list of our developers to add a parameter for this in the design panel. Unfortunately I do not have an eta for this.
You should be good to go after setting a css declartion for this in the custome stylesheet of your email (template).
In case the first code I gave you doesn't work, please try this code instead:
#acymwysidtemplate p {
margin-bottom: 16px !important;
}
Have a nice day.