Originally Posted by friskydrifter
Ok I asked too soon - I worked it out
All i needed to do was edit /etc/httpd/conf/httpd.conf
And change line
DirectoryIndex index.html index.html.var
I'm not sure how that is working but DirectoryIndex is used to define what it should look for to display the default index file, if it's html, php, shtml, etc. What you should be editing for your domain if you want squirrelmail to be the default page is to change your DocumentRoot path to your squirrelmail directory.