Hi dkirsche,
the ManagingEditor is a field in the XML data of the RSS feed to give contact informations about tha manager of the contents that are syndicated:
<?xml version="1.0" encoding="utf-8"?>
<rss version="2.0" xmlns:slash="http://purl.org/rss/1.0/modules/slash/" xmlns:trackback="http://madskills.com/public/xml/rss/module/trackback/">
<channel>
<title>John's Blog</title>
<description>This blog is written by John Smith.</description>
<link>http://www.mydomain.com/Blogs/tabid/54/BlogId/2/Default.aspx</link>
<language>en-US</language>
<managingEditor>johnsmith@managing.com</managingEditor>
<webMaster>admin@localhost.com</webMaster>
...
<item>
...
</item>
<item>
...
</item>
</channel>
Prepopulating that field with the user's email would require modifications to the source code, unfortunately it cannot be done editing the .ascx file. Let me know if you need further explanations.
Best regards,
Dario Rossa