Contact form plugin for Joomla! Inside an article
If you edit the tag manually, you must use # instead of @ in you email address (only in the tag). Also, make sure there is no formatting directly inside the tag. To do so, look into html code and remove any html tag that is not encoded.
example (html view):
{contactformpro mailto="sebastien.chartier#gmail.com" error_message="<p>There was an error</p>" display="popup" style="light" width="400" /}