If you send email posts through Gmail to WordPress, line breaks will be inserted into the post (line breaks aren’t inserted when sent in plain text format via Outlook 2007). In order to remove them, I installed the TinyMCE advanced plug-in and added the “Edit HTML Source” button to the editor. In order to remove the line breaks, I copy the text, click on the “Edit HTML Source” button, and paste the text in the editor box. I then uncheck word wrap, and the line breaks are removed. Press the update button to apply the change, and now the text has no line breaks.