Pasting plain text into email

Even when I copy and paste from Notepad with NO existing formatting, the Constant Contact editor does not keep the format already established IN THE EMAIL. For example, all my headers are 14pt, century gothic, bold, and teal. When I paste in a new headline (from Notepad -- with NO problematic formatting attached), it will not keep the destination formatting that is already in the email. It's very tedious to have to reformat every section of text. Is there a way to paste text into the Constant Contact editor and KEEP the destination formatting?