1) Removed the <author> tag from each <item>. The presence of this tag is ok here but the xsd requires that the content include a valid email address, not just the name string coming from the site config (Forms that pass validation are "test@xyz.com" or "test@xyz.com (Test McTester)" ). And who would want to advertise their real email like that? :)
2) Removed the <author> tag from the <channel>. <author> isn't a valid child element of a channel. There is a child element called <webMaster> that is a close analogue but it also requires content as above.
