Email can be very temperamental especially when you start copy/pasting content from websites or word documents into them. What formats well on a website will not necessarily format well in an email.
You can eliminate this issues by removing the formatting that comes along with pasted content.
- Paste some content into an email section.
- Highlight all the content
- Click the "Tx" icon on the tool bar.
- Formatting will be removed.
- Add back any formatting, like Bold or bullets, you want using the icons on the editor.
Nasty formatting should be removed and you're ready to send your content in an email friendly way.