It was suspended as there was no real site when checking your main domain. Generally that means there's a directory listing showing, or that the default index.html page is the one loading up.
I have unsuspended your account to check, and there's indeed the default index.html page showing on your main domain.
If you use an addon domain in a separate directory it's wise to place a simple index.html page in the public_html folder with links to that add-on domain, or create a redirect.
Please do either of those as soon as possible to avoid future problems for having no site on the main domain.