Do you load your email using a bookmark? There is an obscure setting for bookmarks that directs them to the sidebar instead of the main page area. This usually gets set by clicking a link in a page to bookmark the page instead of using Firefox's built-in add bookmark feature.

To fix that, right-click the bookmark, click Properties, then uncheck the box for "Load this bookmark in the sidebar". Does that work?

jeanmrowden said

I can't access webmail except on the left sidebar, and it is too narrow to read or manage in that form. How do i remove it from home page and see it full screen?

Thanks, that was simple and it worked, brilliant!